Poirot is initially asked to investigate petty thefts and vandalism in the hostel, and easily discovers that most of these acts were committed by resident Celia Austin.

An outbreak of apparent kleptomania at a student hostel arouses Hercule Poirot's interest when he sees the bizarre list of stolen and vandalised items.

These include a stethoscope, some lightbulbs, some old flannel trousers, a box of chocolates, a slashed rucksack, some boracic powder and a diamond ring later found in a bowl of soup – he congratulates the warden, Mrs Hubbard, on a 'unique and beautiful problem'.

Poirot's solution of the petty thefts is unsubtle but effective: once he has threatened to call in the police, Celia Austin quickly confesses to the pettier incidents.

She denies, however, the following: stealing Nigel Chapman's green ink and using it to deface Elizabeth Johnston's work; taking the stethoscope, the light bulbs and boracic powder; and cutting up and concealing a rucksack.

Nigel Chapman admits to having stolen the stethoscope to pose as a doctor and steal some morphine tartrate from the hospital dispensary as part of a bet to acquire three deadly poisons (the other two being digitalin and hyoscine).

When the father discovered this (Medinal is a poison slow to act, and the mother told her husband), he forced him to write a confession and left it with his solicitor together with a letter explaining that it should be presented to the authorities in case of any further wrongdoing by Nigel.

Philip John Stead's review in the Times Literary Supplement of 23 December 1955 began: "Poirot's return to the happy hunting grounds of detective fiction is something of an event.

He is called upon to solve the mystery of a series of apparently trivial thefts at a student's hostel but soon finds himself partnering the police in investigating murder.

After summarising the plot he concluded, "The amount of mischief going on in the hostel imposes some strain on the reader's patience as well as on Poirot's ingenuity; the author has been a little too liberal with the red herrings.

A highly perfunctory going-through-the-paces: the rhyme has no meaning within the story; the plot (drugs smuggled in imported haversacks) is unlikely in the extreme; and the attempt to widen the range of character types (Africans, Indians, students of Freud etc.)

When Poirot comes to lecture to the students about his cases in the same chapter, he retells the story of The Nemean Lion, published in book form in The Labours of Hercules (1947).

In chapter 5 Poirot also remembers Count Vera Rossakoff's "exotic splendour...even in decay", something that he has only observed in The Capture of Cerberus, also from The Labours of Hercules.

A television adaptation, starring David Suchet as Poirot; Philip Jackson as Inspector Japp; Pauline Moran as Miss Lemon; Damian Lewis as Leonard Bateson; Sarah Badel as Mrs Hubbard; Elinor Morriston as Valerie Hobhouse and Jonathan Firth as Nigel Chapman, was broadcast in 1995 in the series Agatha Christie's Poirot.

In common with the rest of the series, the setting is moved back in time from the post-World War II period of Christie's original novel to the 1930s.

Other aspects omitted from the TV adaptation include the red herring of the green ink, the change of the motive for the murder of Celia, the theft of the poison being the only thing taken and the person who takes it (McNabb) and the smuggling involving only diamonds, the inclusion of a Custom and Excise Officer conducting an undercover operation, and the relationship between Valerie and Mrs Nicoletis.