Penny Black planted in Milo's copy of The Hollow Man

The planting of the Penny Black in Milo Motion’s copy of The Hollow Man transformed a theft into a deliberate locked-room stunt. The stamp cover appeared at the precise point where the book’s chapter on locked-room mysteries was about to be read, joining a real crime to the conventions of the fictional puzzle under discussion.

The clue in the book

The riddle’s instruction to look for the lady in the locked room at seventeen was read as a reference to chapter seventeen of The Hollow Man, titled “The Locked-Room Lecture.” If the lady meant Queen Victoria, the wording directed attention to the place where the Penny Black cover was found. The book’s chapter number therefore served both as a literary reference and as a pointer to the planted item.

Planning and opportunity

Julie Hargreaves argued that the Bloodhounds formed a limited pool of possible perpetrators. At an earlier meeting, the group knew that Milo would bring his copy of The Hollow Man to the next gathering; the thief could exploit that advance information by placing the stamp in the book. On this reasoning, if Milo himself was not responsible, the person who planted it had to be sought among those with access to that opportunity.

John Wigfull likewise concluded that the incident was more than an ordinary theft: it was a stunt planned by someone with inside information. The Bloodhounds were due to discuss locked-room mysteries, and Milo’s book contained the famous chapter on the subject. The missing cover was discovered just as Milo was about to read from that chapter, making the timing part of the performance rather than a coincidence.

The locked-boat puzzle

The book had been aboard Milo’s boat for the week, and the boat was kept locked. Wigfull presented those circumstances as a second puzzle: a closed circle of suspects around a book that had supposedly remained in a secure boat. He said the boat was bolted inside at the prow and padlocked outside, and displayed a sturdy-looking padlock as evidence of its security.

Wigfull said that Milo came to the police at once and that he had satisfied himself Milo was not the thief. Milo was genuinely shocked and unable to explain how the cover had appeared in his book. The planting thus made Milo’s boat and book seem to pose a locked-room problem while also placing Milo under suspicion; the evidence here establishes the staged discovery and its apparent conditions, but does not itself identify the planter.