Gilbert Jones—Sid Towers

Gilbert Jones—Sid Towers is a relationship defined by a deception that turned fatal: Jones’s padlock switch created the locked-room trick, while Sid’s curiosity brought him to the boatyard just as Jones was carrying it out. Sid was not the intended victim, but his arrival exposed the scheme and ended in his death; Jones then tried to make the killing appear part of the stamp theft.

The Padlock Switch

Jones had arranged for an extra padlock from Foxton's and switched it while Milo Motion was aboard the narrowboat, a maneuver that would allow Jones to unlock it later. The switch was part of a larger attempt to make the boat’s locked-room appearance serve his theft of the Penny Black. Its success depended on the deception remaining undiscovered—and on nobody arriving while Jones was at work.

Sid’s Arrival and Death

Sid’s interest in the apparent locked-room puzzle brought him to the boatyard. A Dickson Carr enthusiast, he drove out to inspect the narrowboat and came along the towpath while Jones was replacing the original padlock. Jones heard him approaching, hid inside the cabin, and grabbed a windlass. In Diamond’s reconstruction, Jones was frightened and angry and struck Sid over the head, probably intending only to knock him out. The blow killed him.

Jones later confirmed the essential point: he had hit Sid from behind because he wanted to get away, not because he intended to kill him. He believed Sid had not seen him, and said that had Sid survived, nobody would have been the wiser. The distinction between intention and consequence defines their connection: Sid’s arrival was accidental, but the fatal blow made Jones’s elaborate deception a murder case.

Concealment and Consequences

After Sid’s death, Jones’s actions were directed toward covering it up. One possible outcome was that people would assume Sid had stolen the stamp and staged the locked-room trick himself, turning the scheme’s intended misdirection against the dead man. Diamond’s later account links the replacement padlock, Sid’s curiosity, and the fatal confrontation; Jones’s admission confirms that the blow was his and that escape, rather than murder, had been his immediate aim. The padlock trick therefore did more than create a puzzle: its exposure at the boatyard produced the death Jones then needed to conceal.