Cust's arrest

Cust's arrest turns a report of suspicious movement into formal custody, while leaving the meaning of the evidence unsettled. The trail leads from a young woman's account and a man seen leaving a room to a hotel register, a suitcase of silk stockings, and Cust's collapse as he enters a police station; later, the court commits him for trial, with insanity identified as the only possible defence.

The report and the search

The chain of events begins when Mr Ball explains why he and Mary did not come forward immediately. He says he learned of the situation only after news of another murder reached them. Mary then described what she had noticed in a basin; finding the account suspicious, Ball went upstairs himself and found the room empty. A boy in the courtyard had seen a man slipping away, and Ball believed the description fitted the person they were seeking. He persuaded his wife that Mary should go to the police and accompanied her when she was reluctant to do so.

The delay draws a sharp rebuke from Anderson, who notes that the incident occurred more than three hours earlier and asks why they were not told at once. Ball's explanation makes the investigation depend not on a prompt, official report but on the gradual joining of separate observations: news of another murder, Mary's account, Ball's inspection of the room, and the courtyard witness's description. Inspector Crome moves the inquiry forward by asking for the man's description as quickly as possible.

The hotel evidence

The police send two men to the Black Swan. Mr Ball accompanies them, conspicuously pleased with his new importance, while Mary is tearful. About ten minutes later, a sergeant returns with the hotel register and points out the signature. The writing is small and cramped, and the group crowds around to examine it. Crome identifies the significance of the name as A B C, linking the hotel inquiry to the pattern already under investigation.

The luggage provides a more concrete clue. A good-sized suitcase contains numerous small cardboard boxes, which in turn hold silk stockings. Crome congratulates Poirot: the discovery confirms the hunch that has directed the search. The detail connects the suspect's movements with the distinctive merchandise associated with the killings, but the evidence at this stage establishes a lead and a suspected identity, not yet a complete account of the crimes.

Cust enters custody

Later, Cust is described as having reached the end of his strength and no longer looking beyond the ground immediately before him. He walks one foot in front of the other, then raises his eyes to see lights and the words “Police Station.” He gives a little giggle at the coincidence and steps inside, only to sway and fall forward. The narrative presents the station as both destination and threshold: Cust arrives there, but his collapse interrupts the moment of entry and leaves his condition central to what follows.

On a clear November day, Dr Thompson and Chief Inspector Japp visit Poirot to report the outcome of the police-court proceedings in the case of Rex v. Alexander Bonaparte Cust. Poirot has been kept away by a slight bronchial chill. Japp says Cust has been committed for trial. When Hastings asks whether it is unusual for a defence to be offered at this stage, Japp explains that it is the usual course and suggests that the young Lucas hoped to hurry the matter through. He adds that insanity is the only possible defence.

Significance and unresolved responsibility

Cust's arrest assembles clues that appear to point toward him: the witness's description, the hotel signature, and the boxes of silk stockings. Yet the event's aftermath does not present conviction or a settled account of guilt. Instead, Cust's collapse and the court's identification of insanity as the available defence place his mental condition at the centre of the coming trial. The arrest therefore marks a decisive procedural change—from a suspect being pursued to a defendant committed for trial—while preserving the distinction between evidence that implicates him and a final determination of responsibility.