Killing Sid Towers with the boat windlass

Sid Towers’s killing aboard the narrowboat turns Gilbert Jones’s elaborate locked-room scheme into a homicide: discovered in the act of changing a padlock, Jones hid in the cabin and struck Sid with a windlass. He said he meant to make his getaway, not kill him, but Sid’s death made concealment the next stage of the plan.

Background and the Padlock Switch

Jones’s scheme depended on manipulating the boat’s locks. He obtained an extra padlock from Foxton’s and switched it while Milo Motion was aboard, creating the opportunity to unlock the boat later. That carefully arranged mechanism had almost worked as intended: Jones was replacing the original padlock when Sid arrived, unaware that the change would put him in immediate danger. Sid’s interest in locked-room puzzles brought him to the boat. A devotee of John Dickson Carr, he was fascinated by what had happened and drove out to inspect the narrowboat. He then came along the towpath just as Jones was making the switch. Sid’s curiosity intersected with the one moment Jones could not afford to be seen.

The Killing

In Peter Diamond’s reconstruction, Jones heard Sid approaching, hid inside the cabin, and seized a windlass as a weapon. Diamond believed Jones was frightened and angry, and that he struck Sid over the head intending to knock him out rather than kill him. The blow proved fatal. Jones later confirmed that he had hit Sid from behind, explaining that he only wanted to escape and that Sid had not seen him; if Sid had survived, Jones believed the scheme might have remained undiscovered.

Cover-Up and Consequences

Sid’s death was not part of the original plan, but it transformed the crime. Jones had nearly escaped with what Diamond calls a perfect crime; after the blow, everything that followed served to cover up what had happened. One possible explanation was that people would believe Sid had stolen the Penny Black and staged the locked-room trick himself, shifting suspicion from Jones to the victim. Jessica Shaw suspected A.J. was responsible after Sid was killed and did not want the police to find out. She hoped he might get away with it, aided by the possibility that Sid would be blamed for the stamp theft and the apparent locked-room mystery. The killing thus left Jones’s ingenious arrangement exposed to the very scrutiny Sid’s fascination had prompted, while drawing Jessica into the effort to conceal the truth.