September 12

September 12 is the date on which Camilla Tressilian was murdered, a fixed point around which the investigation reconstructs the events of Monday night and tests claims about the preceding evening. The date matters not only as the crime’s calendar designation but as a means of separating what witnesses actually saw from what they later inferred.

The Date of the Murder

When Superintendent Battle arrests Audrey Strange, he identifies the charge as the murder of Camilla Tressilian on Monday, September 12. The arrest gives the investigation a precise temporal anchor: the questioning and examination of evidence that follow concern a killing assigned to that Monday, rather than an unspecified point in the household’s recent past.

The Night Before

Battle’s account places an important household event after Nevile Strange had left Lady Tressilian the night before the murder: Lady Tressilian rang for her maid. In the chronology of a Monday killing, this locates the call on the preceding evening and makes the hours before September 12 part of the inquiry’s reconstruction. The detail is presented as a step in Battle’s account, not as a conclusion about who committed the murder.

Sunday and Monday in the Disputed Account

MacWhirter describes going to Stark Head on Monday night, at approximately eleven o’clock, and looking across toward Gull’s Point while lost in thought. His account places him at the headland on the night of September 12, but he later clarifies that he did not see anyone climbing a rope. He says that he could not have seen such a thing because his visit to Stark Head had actually been on Sunday night, not Monday.

That distinction changes the status of the apparent eyewitness evidence. MacWhirter explains that he inferred what might have happened from the suit and regarded the discovery of a wet rope in the attic as confirmation of his suppositions. His statement therefore distinguishes an observation from an inference: the rope and the clothing informed his reconstruction, but he had not witnessed a person climbing it on the night of the murder.

Evidence and the Investigation

The investigation also tests physical evidence against recollection. A doctor is asked whether he can swear that the weapon was the one used in the crime, and Battle later confronts Nevile with the fact that he had recognised Lady Tressilian’s niblick as his property and that his fingerprints were found on it. These exchanges belong to the inquiry into the September 12 murder; they show why identification, possession, and the timing of a claimed sighting must be considered separately rather than treated as interchangeable proof.

The date thus functions as more than a label in the arrest charge. By fixing the murder to Monday, September 12, it exposes the significance of the Sunday-night/Monday-night discrepancy and gives Battle a basis for examining how the story of the rope was assembled. The chronology helps distinguish the murder’s established date from the evidence and suppositions offered to explain what happened around it.