The Motley Few, Act I

**Contains major plot spoilers for The Affair at the Victory Ball.**​


“To Harlequin the invisible.”
Agatha Christie
Agatha Christie

A Singular Dedication

This dedication by Agatha Christie in her collection of short stories The Mysterious Mr. Quin is wholly unique because it marks the only time Christie dedicated one of her works to one of her fictional characters.  It is apposite, however, as Harley Quin was probably her favorite among her creations.  In her Autobiography, Christie states,

Actually my output seems to have been rather good in the years 1929 to 1932: besides full-length books I had published two collections of short stories. One consisted of Mr. Quin stories. These are my favourite. I wrote one, not very often, at intervals of perhaps three or four months, sometimes longer still. Magazines appeared to like them, and I liked them myself, but I refused all offers to do a series for any periodical. I didn’t want to do a series of Mr. Quin: I only wanted to do one when I felt like it. He was a kind of carry-over for me from my early poems in the Harlequin and Columbine series.

Unlike Hercule Poirot and Miss Marple, Harley Quin is not a detective.  Rather he is an ephemeral being, arriving at the scene of mysterious circumstances (often involving romantic entanglements) to guide Mr. Sattherthwaite (who could be considered the detective in stories involving Mr. Quin) to the truth about the situations.  Although he wears a typical dark suit, it is often described that the light hits him in certain ways to produce effects of a colorful motley or black domino mask.  Christie continues,

Harley Quin, Agatha Christie
First UK edition, 1930
Mr. Quin was a figure who just entered into a story--a catalyst, no more--his mere presence affected human beings. There would be some little fact, some apparently irrelevant phrase, to point him out for what he was: a man shown in harlequin-coloured light that fell on him through a glass window; a sudden appearance or disappearance. Always he stood for the same things: he was a friend of lovers, and connected with death. Little Mr. Satterthwaite, who was, as you might say, Mr. Quin’s emissary, also became a favourite character of mine.

The Mysterious Mr. Quin was published in 1930, shortly after the death of Christie’s brother Monty from a stroke possibly related to wounds suffered in World War I.

The character of Harley Quin only appeared in 14 stories, assembled into one collection (The Mysterious Mr. Quin) and as part of other collections (The Harlequin Tea Set and Problem at Pollensa Bay and Other Stories).  Apart from a silent movie in 1928, there has never been a cinematic or television adaptation of the works, and Harley Quin remains one of Christie’s lesser known characters.

Christie and the Harlequinade

As mentioned in What’s in a Dame?, Christie participated in amateur theatricals in her youth, and a common performance piece at the time was the Harlequinade.  Derived from the Italian Commedia dell’Arte, the Harlequinade as a pantomime, play, or ballet tells the story of Harlequin (from the Italian “Arlecchino”), a servile rogue with a predilection to aid lovers with the help of magic and invisibility.  He romantically pursues Columbine, an intelligent and compassionate servant.  His rival for her affections is Pierrot, who downplays his disappointment when spurned by playing tricks and pranks.  The character of Pierrette was a female counterpart to and love interest of Pierrot.  Punchinello and Pulcinella may also be servants but more often seem to be the masters in a situation, imposing figures with long noses and broad bellies.  The Harlequinade would tell a variety of stories with this cast of characters, often involving some scheme to separate Harlequin and Columbine, and Harlequin would use a magical stick called a “slapstick” to resolve the silly situations – this is the origin of the term slapstick humor.

harlequin, pierrot, slapstick
Commedia dell'arte characters Harlequin (left) and Pierrot, illustration on paper, c. 1874–88; in the Rijksmuseum, Amsterdam. Courtesy of the Rijksmuseum, Amsterdam; Gift of F.G. Waller, Amsterdam

Pierrot was traditionally played by an actor without a mask and wearing white make-up, which is thought to be the origin of white clown make-up. Harlequin was traditionally masked with a dark brown or black mask, suggesting African influences on the character but more likely related to systemic racism within theatre and society in relation to the character of a servant. Punchinello appears to be the origin of the character Punch from Punch and Judy puppet shows.

Inspired by these theatrical scenes, young Agatha composed a great deal of poetry in her childhood.  Some of the poems she wrote around age 17 were published in The Road of Dreams in 1924, including verses about Harlequin, Columbine, Pierrot, and Pierrette; the young Christie even set her Harlequin poems to music.  “Harlequin’s Song” describes the character with,

I pass
Where’er I’ve a mind,
With a laugh as I dance,
And a leap so high,
With a lightning glance,
And a crash and a flash
In the summer sky!
I come in the wind,
And I go with a sigh…
     And nobody ever sees Harlequin,
     “Happy go lucky” Harlequin,
Go by…
[…]
I must play my part…
     For never a soul has Harlequin,
     Happy go lucky Harlequin,
Only a broken heart…

Christie’s grandmother also owned a set of Dresden figurines from the Italian comedy, which are still part of the family’s collection. Drawing inspiration from her love of this set of characters, particularly Harlequin, Christie included them (and a similar set of figurines) in her first short story to feature Hercule Poirot, The Affair at the Victory Ball.  The story was published in Sketch in 1923 and tells the story of the murder of Lord Cronshaw at the Victory Ball, which was followed closely by the death of the actress Coco Courtenay by cocaine overdose.

A Victorious Affair

Lord Cronshaw, 25 years of age, was rumored to be engaged to Ms. Courtenay.  The pair attended the Victory Ball, dressed as Harlequin and Columbine, in the company of Punchinello (Lord Eustace Beltane, uncle to Cronshow who would inherit his title), Pulcinella (Mrs. Mallaby, an American widow), Pierrot (Chris Davidson, an acting friend of Coco’s), and Pierrette (Mrs. Davidson, Chris’s wife), in costumes inspired by Lord Beltane’s figure collection.  The mood was tense between Cronshaw and Courtenay, who requested Chris Davidson escort her home following dinner.  After accompanying the tearful actress home, Davidson returned to his flat in Chelsea.

Harlequinade figurines

At the Ball, Lord Cronshaw was scarcely seen by the party for the rest of the evening until 1:30 a.m., when he was spotted by a Captain Digby.  He asked Lord Cronshaw to rejoin the group, but he had not done so after several minutes.  A small search party was formed with Digby, Mrs. Davidson, and Mrs. Mallaby, who discovered Cronshaw stabbed to death in the supper room.  On his body was a small enamel box half filled with cocaine and with the name “Coco” inscribed in diamonds.  Also discovered tightly clenched in the Lord’s fist was a small green pompon, with ragged threads as though it had been pulled forcefully from its source.  The next morning, the body of Coco Courtenay was found in her bed, her death due to an accidental or intentional overdose of cocaine.

These facts of the case are related to Hercule Poirot by Chief Inspector Japp, whose highest talent, according to Captain Hastings, “lay in the gentle art of seeking favours under the guise of conferring them!”  Poirot visits Lord Beltane to view the original sculptures and the Davidson home to view the Pierrette costume, which had green pompons.  At the conclusion of this investigation, Poirot arranges for a Harlequinade of his own, hiring actors to portray each of the members of the Cronshaw party.  Through this elaborate reconstruction, Poirot reveals that Chris Davidson had killed Harlequin and worn a duplicate costume to pose as Lord Cronshaw at 1:30 a.m., several hours after the original Harlequin had been murdered.

Central to the dispute between Davidson and Cronshaw was the use of cocaine by Ms. Courtenay.  Lord Cronshaw strongly disapproved of the use of the drug and had demanded Coco’s supply earlier in the evening; therefore, Coco’s enamel box was found on his body.  Davidson, who supplied cocaine to Coco, murdered Cronshaw to prevent his exposure as a drug trafficker.  While escorting Coco home, he was able to provide her with more cocaine, likely encouraging her to take a larger dose out of spite for Cronshaw’s objections.  The tragic result was the death of the young actress, as well.

By viewing the figurines, Poirot was able to ascertain that the elaborate rump and ruffle of the Punchinello costume would have prevented Lord Beltane from changing into the Harlequin costume without assistance.  The two women were eliminated because Cronshaw was stabbed with a dull table knife, which would have required considerable strength.  And upon visiting the Davidson’s house, Poirot noted that the green pompon missing from the Pierrette costume was cut with scissors rather than being torn off, as the pompon in the fist of Cronshaw was; therefore, the pompon was from Pierrot’s costume.  These facts pointed directly to Chris Davidson as the perpetrator, who stabbed Cronshaw shortly following dinner and before returning Coco Courtenay home.  Presumably, Davidson had a second Harlequin costume made before the Victory Ball expressly for the commission of his crime, but this is not detailed in the story.

Chris Davidson and his wife as Pierrot and Pierrette from the Acorn adaptation, 1991

True Crime Inspiration

This story was very obviously inspired by the death of Billie Carleton (whose given name was Florence Leonora Stewart), a young actress who died from a cocaine overdose after attending a Victory Ball at the Royal Albert Hall in 1918.  Carleton was close friends with Reginald DeVeulle, a dressmaker who reportedly hosted opium parties at his house.  DeVeulle, dressed as Harlequin, attended the Victory Ball in the company of his wife Pauline (costume unknown).  While at the Ball, DeVeulle allegedly provided a supply of cocaine in a small silver or gold (reports vary) box to the actor Lionel Belcher to pass to Carleton.

Billie Carleton, National Portrait Gallery

After the festivities at the Ball, Belcher and two other actresses, Olive Richardson and Irene Castle, returned to Carleton’s apartment to continue their revelry.  It is not known what exactly transpired, but Carleton retired to bed early in the morning, and the others returned to their respective homes.  Later in the morning, Carleton’s maid noticed she had stopped snoring; the maid was unable to wake her, and she was pronounced dead a short time later.

Carleton’s death was ruled to be the result of cocaine overdose.  The police and public focused on her decadent lifestyle, as she was known to attend opium parties and her reputation had cost her at least one role.  Looking to blame a “foreign” influence on her behavior and death, Carleton’s friend and costumer Reggie de Veulle, who allegedly supplied her with cocaine, was ruled to be culpable for her death at the coroner’s inquisition but then acquitted on a formal charge of manslaughter; however, he was charged with supplying cocaine to Carleton.  A husband-and-wife duo, Lo Ping Yu and Ada Lo Ping, also received several months of jail time for their roles in supplying opium to the dead actress, among others.

Reginald De Veulle, Billie Carleton
Daily Sketch from January 2019 detailing the coroner's inquest of Billie Carleton

Christie was no doubt inspired by this sensational story from a Victory Ball in 1918.  However, her story added the murder of Lord Cronshaw in the guise of Harlequin.  Cronshaw adamantly opposed drug taking and was murdered for his beliefs, so this appears to be a way for Christie to reclaim one of her favorite characters as a noble martyr after being used as a costume by a perceived villain such as de Veulle.

Christie even borrowed the name “Cronshaw” from a previous criminal lawsuit that involved Reggie de Veulle, where one of the victims was named William Cronshaw.

Cocaine possession was illegal in Britain following the Defence of the Realm Act 1914, which was passed in 1916.

Cocaine use is featured in several other Christie novels, including Peril at End House, Hickory Dickory Death, and the Labours of Hercules.  Christie seems to have some sympathy for addicts, but her knowledge of the drug’s effects was more often used to typify the questionable morality of some of her characters.

Physiological Effects of Cocaine

Cocaine is a tropane alkaloid.  It exerts physiological effects by binding proteins within the body, most notably the serotonin transporter, dopamine transporter, and norepinephrine transporter.  These three transporters are involved in the transmission of the respective neurotransmitters from neuron to neuron in the central nervous system.  When cocaine binds, the reuptake of the neurotransmitters is reduced or eliminated, causing prolonged stimulation of the downstream neurons.

Cocaine molecule
Cocaine molecule

Inhibition of the reuptake of the neurotransmitter serotonin is the primary function of selective serotonin reuptake inhibitors (SSRIs), which are popular antidepressant medications.

Additionally, cocaine binds to voltage-gated ion channels in the heart, which can result in cardiotoxicity.  These channels are present on cellular membranes and control the amount of electrolytes present within cells versus between cells.  Electrical changes in the cellular membranes control whether the channels are open or closed.  Therefore, an interruption in the function of these channels can lead to deadly electrolyte imbalances.

Electrolytes are ionic (or positively or negatively charged) forms of mineral elements, for example, sodium (+1), potassium (+1), and calcium (+2).

Research has shown that the interaction of cocaine with dopamine receptors is the primary mechanism that drives addiction.  In animals genetically manipulated such that their dopamine receptors do not bind cocaine, addictive behaviors do not manifest when the animals are provided and/or deprived of cocaine.  However, the interaction between cocaine and the serotonin receptor may cause convulsions, so the displacement of serotonin does play a role in cocaine toxicity.  Lastly, the inhibition of norepinephrine signalling by cocaine can lead to rapid increases in blood pressure.

Cocaine also interacts with cholinergic receptors and prevents reduction in heart rate.  This interaction would cause an increase in heart rate (similar to atropine as described in Tuesday Night Fever).  Coupled with the effect on voltage-gated channels and the increase in blood pressure from norepinephrine inhibition, damage to the heart is a central component of cocaine toxicity.  Because the neurotransmitter receptors have a higher affinity for cocaine (in other words, cocaine can bind strongly at lower concentrations), the central nervous system is affected first; for example, the user begins to have seizures.  With higher doses or concentrations of cocaine, the voltage-gated ion channels are then affected, and the cardiotoxic effects of cocaine are seen.  The interference of cocaine with voltage-gated sodium, potassium, and calcium channels will cause cardiac arrhythmias, which are abnormal changes in heart rate.  These arrhythmias can cause sudden cardiac death in cocaine users, even without any pre-exisiting cardiac conditions.

Christie does not provide specific details of Coco Courtenay’s death (nor other characters who perish from cocaine), but it is plausible that the victims suffered sudden cardiac death or a severe seizure.  At Reggie de Veulle’s trial, a doctor testified that Billie Carleton had cocaine present in her nostrils and died as a result of an increase in blood pressure and the formation of blood clots in her heart due to the cocaine, which starved her body of oxygen and led to death.  Interestingly, the doctor who attended Carleton the morning of her death stated he administered strychnine (and brandy) in an attempt to resuscitate the actress.  She was 22 years old at the time of her death.

calcium channel, potassium channel, cholinergic receptor
Some molecular targets of cocaine

Rigor Mortis

Another intriguing scientific principle that features in The Affair at the Victory Ball is rigor mortis, the stiffening of muscles following death.  Because Chris Davidson donned a harlequin costume and impersonated Lord Cronshaw within 10 minutes of his cohorts finding the body, a doctor testified that the stiffening of Cronshaw’s body was abnormal.  However, because Cronshaw had been killed several hours prior, this was actually the natural process of rigor mortis.  In addition to suggesting the time of death, it also led to the discovery of the important clue of the green pompon, which was clenched in Cronshaw’s fist.

Skeletal muscle diagram

Immediately following death, all muscles in the body are fully relaxed.  Within the first hour, some of the smaller muscle groups (such as the jaw and eyelids) begin to stiffen, followed by larger muscle groups.  The timing of onset and development of rigor mortis can vary considerably due to factors such as the ambient temperature, and rigor mortis develops more quickly in higher temperatures.

In a living body, the functional unit of skeletal muscles, myofibrils, comprise the myofilaments actin and myosin.  To contract, they are acted upon by adenosine triphosphate (ATP), which is an enzymatic cofactor that is involved in intracellular energy transfer.  In the presence of ATP, actin and myosin form the compound actomyosin, which physically shortens during muscle contraction.  Shortly after death, the production of ATP ceases, and the crossbridges formed between actin and myosin no longer break down.  This results in the muscle stiffening and shortness that is characteristic of rigor mortis.  

An enzyme is a protein that catalyzes chemical reactions by reducing the energy required, and they are not consumed by the reaction. An enzymatic cofactor is a molecule that binds to a specific region of an enzyme and is required for the normal function of the enzyme.

Diagram of muscle contraction. After death, ATP is not available for Step 4; therefore, the muscles remain contracted.

Rigor mortis may take 6 to 18 hours to fully take effect but can occur more quickly in higher temperatures.  If the individual who dies was engaged in vigorous exercise, such as a struggle, before death, the onset may even be more rapid; this was likely the case with Lord Cronshaw as he attempted to fight off Chris Davidson.

The discovery of the green pompon clasped tightly in Cronshaw’s fist may be less scientifically plausible.  A theory of “cadaveric spasm” posits that rigor mortis can instantly appear following death based on the appearance of dead bodies during World War I and World War II.  However, there remains no credible biological explanation for such a phenomenon, and it is more likely that rigor mortis set in with the typical delay during the wars, but the bodies had continued to be affected by explosions on the battlefield until it fully set in. 

rigor mortis, cadaveric spasm
Leaves clasped within the hands of a body recovered from water, from Toskos and Byard, 2016

Consequently, it is highly unlikely that Lord Cronshaw’s fist remained tightly clasped around the pompon from the time just before his death until his discovery.  Because all muscles relax after death, he would have dropped the pompon, but as long as it remained just beneath the palm of his hand, he would have re-grasped it when rigor mortis took effect.  This is possible but somewhat unrealistic given the short period of time between his death and the discovery of his body.  Nevertheless, the inclusion of this plot point illustrates Christie’s basic understanding of rigor mortis.

The next blog post will further explore the characters of Harley Quin and Mr. Satterthwaite and describe medical conditions whose names are derived from the character of Harlequin.

The Motley Few, Act II

**Contains major plot spoilers for The Coming of Mr. Quin and The Harlequin Tea Set and a minor plot spoiler for The Chocolate Box.**​


The Harlequinade Continues

It is fitting that Christie drew upon her favorite theatrical characters and grandmother’s figurines for her first Poirot short story.  In quick succession, she would publish her first Harley Quin story, The Coming of Mr. Quin (originally titled The Passing of Mr. Quin), in 1924.  The story begins at a New Year’s Eve party attended by Mr. Satterthwaite, who was:

Sixty-two--a little bent, dried-up man with a peering face oddly elflike, and an intense and inordinate interest in other people’s lives. All his life, so to speak, he had sat in the front row of the stalls watching various dramas of human nature unfold before him. His role had always been that of the onlooker. Only now, with old age holding him in its clutch, he found himself increasingly critical of the drama submitted to him. He demanded now something a little out of the common.
Mr. Satterthwaite from Agatha Christie's Death on the Cards by Modiphius, 2019

Satterthwaite is shortly to have his wish granted but first wonders about a couple who are attending the party, the Portals.  Alex Portal was of “usual good sound English stock,” but his wife, Eleanor, was Australian, and Satterthwaite particularly wondered why she dyed her light hair black.  He also noted that Alex seemed to be afraid of her, although it was obvious he loved her.

The other party attendees recount the story of Derek Capel, who formerly owned the house in which they are gathered.  Capel suddenly shot himself one day without an apparent reason.  While discussing the possibility of the house being haunted, three loud knocks are heard at the front door, ushering the arrival of Mr. Harley Quin:

Harley Quin, harlequin
Framed in the doorway stood a man’s figure, tall and slender. To Mr. Satterthwaite, watching, he appeared by some curious effect of the stained glass above the door, to be dressed in every colour of the rainbow. Then, as he stepped forward, he showed himself to be a thin dark man dressed in motoring clothes.

Quin says his car has broken down and joins the party guests; “as he sat, some effect of the firelight threw a bar of shadow across his face which gave almost the impression of a mask.”  Quin reveals that he had also met Derek Capel, and the group continue discussing his mysterious suicide.  Mr. Satterthwaite notices that Eleanor Portal is now eavesdropping on the conversation and concludes that the entire evening was orchestrated by Mr. Quin: “he was at the heart of the mystery pulling the strings, making the puppets work.”  

In due course, the full story of Capel’s death is recounted.  He had announced his engagement but could not identify to whom, which led his companions to think that the woman was either currently or very recently married.  Subsequently, the post arrived with newspapers and letters; Capel opened the newspaper, then went upstairs and shot himself.  This had occurred around the time that the Appleton case was in the newspapers, wherein an “old curmudgeon” (with a young and very fair wife) had been poisoned with arsenic or strychnine.  The wife was suspected, but there was not enough evidence to find her guilty at trial.

Mr. Quin guides the fellow men through the events.  Capel was in love with Mrs. Appleton and had added strychnine to her husband’s decanter of port about a week before the elderly man’s death.  Apparently an amateur toxicologist, Quin explains, “strychnine is not very soluble unless it is in the form of hydrochloride.  The greater part of it, put into the port, would be taken in the last glass, perhaps a week after he left.”  Reading in the newspaper that Appleton’s body was to be exhumed, Capel happens to see a police officer approaching the house from his window.  The newspaper is a few days late because of a sizeable snowstorm, and Capel assumes that the officer has arrived to arrest him for murder, and he shoots himself.  In actuality, the officer was returning a dog.

During his brief appearance at the party, Quin makes a special connection with Mr. Satterthwaite but departs once this solution is revealed.  His parting words are:

I must recommend the Harlequinade to your attention. It is dying out nowadays--but it repays attention, I assure you. Its symbolism is a little difficult to follow--but the immortals are always immortal, you know.

After Quin leaves, Mr. Satterthwaite observes a scene between Mr. and Mrs. Portal.  Alex asks her for forgiveness, now realizing the truth that she, as Mrs. Appleton, had not killed her husband.  Harley Quin’s intercession on that evening had saved their marriage and her life, as she admits that was going to kill herself that night: “that man–that chance passerby, saved me.”

One of the locations where Mr. Satterthwaite happens to meet Harley Quin is a restaurant called Arlecchino, after the original Italian for “harlequin.”

The other stories in the collection follow a similar presentation, with Mr. Satterthwaite finding himself in a situation involving a pair of lovers in trouble–from a haunted window, mysterious disappearances, hidden identities, and death.  The stories are not traditional Christie mysteries with an overt crime that requires solving from a brilliant detective but rather puzzling tales and circumstances that Harley Quin clarifies by aiding Mr. Satterthwaite in his ratiocination.  The review in the New York Times Book Review stated, “To call the tales in this collection detective stories would be misleading. For all of them deal with mystery and some of them with crime, they are, nevertheless, more like fairy tales.”

Although the collection of stories was well-reviewed, true to his nature, Harley Quin essentially disappeared from Christie’s subsequent literary output.  The character appeared in just two more stories, which were included in other collections: The Love Detectives and The Harlequin Tea SetNevertheless, Harley Quin is a unique and memorable character among all the characters created by Christie, and as he was beloved by her, these stories are highly recommended.

harlequin, Harley Quin

The Harlequin-inspired stories serve to almost bookend Agatha Christie’s career as the first Poirot (The Affair at the Victory Ball) and last ever (The Harlequin Tea Set) published short stories.  The Passing of Mr. Quinn was the first British film adaptation of one of Christie’s works.

The Harlequin Tea Set

The final story to feature Harley Quin, The Harlequin Tea Set, was also the last story of Christie’s to be published, in 1971.  In the story, Mr. Satterthwaite is waylaid by car troubles on his way to visit acquaintances in the country.  He passes the time at The Harlequin Cafe and reflects on his old friend, Harley Quin,

It was the word “harlequin” of course which had remained fixed in Mr. Satterthwaite’s mind, although just far enough back in his mind so that it had been difficult to recall it. The gay colours. The harlequin colours. And he had thought, wondered, had the absurd but exciting idea that in some way here was a call to him. To him specially. Here, perhaps, eating a meal or purchasing cups and saucers might be his own old friend, Mr. Harley Quin. How many years was it since he had last seen Mr. Quin? A large number of years. Was it the day he had seen Mr. Quin walking away from him down a country lane, Lovers’ Lane they had called it? He had always expected to see Mr. Quin again, once a year at least. Possibly twice a year. But no. That had not happened.
First US edition of The Harlequin Tea Set and Other Stories, G. P. Putnam's Sons, 1997

He admits to himself that he misses Mr. Quin and hopes that he shows up because when he did, it “was always an announcement that something was going to happen.”  A very short time later, Mr. Quin indeed arrives, the sunlight creating a “festoon of colours” from his plain black suit.  The two friends quickly become reacquainted, and Mr. Satterthwaite describes the family of Tom Addison, to whom he is on his way to visit.

The Harlequin Tea Set
The somewhat-complicated Addison family tree

It has been many years since Satterthwaite had last seen his friend, and Tom’s family has changed in the intervening time.  Tom and his late wife had two daughters: Lily, who was Satterthwaite’s goddaughter, and Maria, who died during childbirth.  Lily had also died in a car accident, leaving behind a son, Roland.  Roland’s father Simon remarried a woman named Beryl, who had a young son named Timothy.  Timothy and Roland are now young men in their early 20s and live with their family in a country home named Doverton Kingsbourne, where Satterthwaite is traveling.

Coincidentally, Beryl arrives at The Harlequin Cafe to buy some of the harlequin teacups to replace some that had broken earlier in the day.  Satterthwaite introduces himself and Harley Quin, who is also invited to join the family for tea, but he declines as he is “only passing by.”  Quin departs just as Satterthwaite’s car is returned, providing an enigmatic word that he thinks will be of use to Satterthwaite: Daltonism.

Upon arriving at Doverton Kingsbourne, Satterthwaite is reminded of the meaning behind the word when he sees his old friend Tom Addison wearing one red and one green slipper, but the reader is provided no additional detail as to the condition.  Satterthwaite sees Timothy and Roland for the first time in many years and remarks to himself that Timothy looks more like Lily than her biological son Roland.  Each attendee of the gathering has a different color tea cup; Timothy has a red cup, while Roland has a yellow cup.

While he watches the family and especially Beryl, Satterthwaite increasingly feels as if something important is going to happen, as portended by his meeting Harley Quin earlier that day.  Beryl brushes Timothy’s red cup off the table, shattering it, and she replaces it with a pale blue cup next to Tom’s pipe.  When Timothy’s cousin Inez accuses him of drinking from her cup, since it is now a blue cup instead of a red one, Timothy claims it must be his cup because it is right where he left it by the pipe.  He raises the cup to drink from it when suddenly the entire situation is made clear to Satterthwaite, who quickly tells Timothy not to drink from the cup.

An Ishihara color test plate. Readers with normal vision will see the number "74," readers with red-green colorblindess will read the number "21," and readers with total colorblindness may read no numbers.

Satterthwaite reveals that Daltonism refers to red-green colorblindness and that Timothy is afflicted by this condition, which therefore made him unable to discern between the two teacups.  Satterthwaite also realizes Timothy has inherited his colorblindness from his grandfather Tom (with his mismatched slippers).  He surmises that Beryl exchanged the identity of her son with Roland, the heir to Doverton Kingsbourne, when both boys were young in order to ensure her son would inherit Tom’s estate.  Threatened with confrontation, Beryl flees.

Mr. Satterthwaite receives a note from Harley Quin, congratulating him on his success in preventing a murder, but the two friends are never to meet again in the fictional works of Agatha Christie.

Daltonism

Daltonism is another term for protanopia, which is colorblindness resulting from insensitivity to red light, causing confusion of greens, reds, and yellows.  This pattern of colorblindness is caused by alterations in the proteins responsible for the discernment of light wavelengths due to gene mutations on the X chromosome.  Because women have two X chromosomes, they are typically only carriers of the condition, and it is present in male relatives with one X chromosome.  Women can be affected by colorblindness due to mutations in other genes not on the X chromosome, but this is very rare.  It is also possible that a woman may inherit mutated X chromosomes from both parents (an affected father and a carrier mother), but this is also rare.

The name Daltonism was applied to this condition because the chemist John Dalton provided the first written account of the affliction suffered by him and his brother in 1798.  The inheritance pattern of red-green colorblindness was identified in the late 1960s, and Agatha Christie incorporated this recent scientific discovery into one of her mysteries, as she had done throughout her career.  Christie also used colorblindness as a clue in a Hercule Poirot short story, The Chocolate Box, published in 1924.

X-linked recessive inheritance pattern

Harlequin Medical Disorders

While there are no known forensic science or criminology principles directly related to the Harlequinade, there are two rare but noteworthy skin disorders (and a third that is less uncommon) whose names are at least partially derived from the character of Harlequin.

Harlequin color change, or unilateral erythema

Harlequin color change, or unilateral erythema, is a harmless condition observed in approximately 10% of newborn babies and occurs when half of the baby’s skin exhibits a red color with no change in the other half.  The color change is well demarcated, as with a harlequin costume that is half red and half white.  Scientists speculate that the condition results from a temporary imbalance of the blood vessels in the skin that presents in newborn babies because their hypothalamus is continuing to develop.  The hypothalamus is the body’s homeostatic center, regulating body temperature and many other autonomic (or involuntary) functions.

Another minimally complicated condition — both from scientific and quality-of-life perspectives — is harlequin syndrome.  Like the harlequin color change just described, harlequin syndrome produces unilateral flushing and sweating in the affected person; one-half of the body will appear red while the other half is unchanged.  This is a relatively rare condition, and no definitive cause has been identified.

Based on case reports, it is hypothesized that the condition results from damage to nerve bundles in the head and neck, possibly due to trauma, autoimmune conditions, tumors, or strokes.  Once these nerve bundles are damaged, their communication with half of the body is reduced or eliminated while they maintain normal communication with the other half.  Consequently, in response to a stimulus such as increased body temperature, the half of the body with nervous communication intact will flush and sweat, and the other half of the body will remain unaffected.

Harlequin syndrome may be uncomfortable and embarrassing but is not life threatening, and many patients require no treatment.  In extreme or complicated cases, such as those involving a tumor, surgery may be performed to remove the tumor.  If the damaged nerve bundle can be identified, it can be removed via a surgical procedure called sympathectomy or treated with botulinum toxin.  With these treatments, all signaling from the nerve bundles would be disrupted, so in response to an increase in body temperature, neither side of the body would flush or sweat.

Botulinum toxin (common brand name: Botox) is produced by Clostridium botulinum and is used medically to block nerve signalling for the treatment of wrinkles, excessive sweating, and migraine headaches. It also causes the foodborne illness, botulism, which can be fatal.

The other rare and much more severe medical condition with a name inspired by the Harlequinade is harlequin-type ichthyosis.  This extremely rare genetic disease is almost always fatal, with most historical cases surviving no more than two days after birth.  The condition is characterized by the hardening of the outer layer of the skin, the stratum corneum, which forms armor-like and diamond-shaped plates.  Because the outer layer of skin is so thick and rigid, it distorts the facial features and forms red fissures in the skin between the hard plates.  This appearance led to its appellation of “harlequin-type.”

“Ichthyosis” literally means “fish skin condition.”

In the United States, the incidence of harlequin-type ichthyosis is about 1 in 500,000 live births.  The condition is inherited through an autosomal recessive pattern, which is similar to the X-linked recessive inheritance pattern of Daltonism described previously, so both parents need to have one affected copy of the gene responsible.  Through familial studies, researchers have identified a mutation in the ABCA12 gene that results in the deadly skin disease.

Autosomal recessive inheritance pattern

The ABCA12 protein is a member of the ATP-binding cassette (abbreviated ABC) transporter protein family; these channels are embedded in the phospholipid bilayer (or outer membrane) of cells and use energy from ATP (the molecule also involved with muscle contraction) to transport lipid (or fatty) molecules across the membrane.  Because the lipids move from an area of lower concentration to an area of higher concentration (in other words, against a concentration gradient), this transport requires an input of energy from ATP.  In the epidermal cells found in the skin, these lipid molecules are produced in organelles called lamellar granules. Organelles are membrane-bound areas within a cell that perform specialized functions; for example, the nucleus is the organelle that contains its genetic material.

The function of the ABCA12 protein in healthy skin (A) and harlequin-type ichthyosis (B), from Hovnanian 2005

The molecules produced and exported by the lamellar granules are used in the stratum corneum, the outermost layer of the skin, to maintain the physical barrier of the skin as well as promote the natural sloughing off of skin cells and preservation of the layers of skin underneath.  In harlequin-type ichthyosis, the genetic variations in the ABCA12 gene produce a transporter protein that is incomplete or misshapen and therefore the normal cellular functions of the stratum corneum are severely compromised.  This is called a loss-of-function mutation.

The skin is an integral part of the body’s innate immune system because it provides a powerful physical barrier to insults from pathogens like bacteria and viruses, environmental contamination, and chemical effects.  In any condition where the skin’s normal function is impaired, the individual is at a higher risk of infection.  In harlequin-type ichthyosis, the fissuring of skin between the hard plates can allow for invasion by bacteria and viruses, leading to systemic infections that can be deadly.  There is also some evidence that the production of immune factors within the lamellar granules is impaired, further compromising the immune system.

Additionally, the physical constriction resulting from the skin’s rigidity leads to difficulties with feeding, as an infant would not be able to move her lips properly to suckle, and with breathing because the skin around the chest is too tight to allow for adequate inhalation and exhalation.  Infants with this condition are immediately treated in the neonatal intensive care unit to support feeding and breathing and prevent infection.

Harlequin-type ichthyosis is primarily treated with retinoids, which are vitamin A derivatives that promote the sloughing off of the hardened skin scales and also reduce the formation of new scales.  The skin barrier is supported through applying lotions and emollients, especially those with small amounts of salt, urea, or glycerol.  Often, the hardened scales on the fingers need to be removed surgically to prevent death of the tissue from constricted blood flow.  Antibiotics are used to prevent or treat bacterial infections.  With modern intensive treatment, babies born with this once-fatal condition can survive to early adulthood.  Because this disease is so rare and treatments continue to improve, it is not yet known how much survival has increased, but the future holds promise for individuals with harlequin-type ichthyosis.

Constriction of the fingers in harlequin-type ichthyosis, from Glick et al, 2017

Repaying Attention

The naming of these medical conditions demonstrates the continued prevalence of the character of Harlequin in Western society.  Of course, this author would be remiss if they did not mention the Detective Comics character also named Harley Quinn (with 2 n’s), created by Paul Dini and Bruce Timm as a female sidekick to the Joker.  Although she has no relation to the work of Agatha Christie, the author would likely be pleased that the “Happy go lucky” Harlequin remains relevant for a new generation.