He knows when the enemy will come. Does he know for whom?
A character takes a warning seriously but protects against the wrong danger. Make the mistaken assumption shape the precautions.
Move a character away from a place at predictable times by offering something they have a reason to accept.
Full solution of The Red-Headed League.
Pawnbroker Jabez Wilson is offered paid copying work at another office. His assistant volunteers to run the shop while he is away.
The job pays four pounds a week but requires Wilson to remain at the office from ten to two. Holmes later explains that the arrangement kept him away while criminals tunneled from his cellar toward a bank.
If the target ignores an obviously impossible offer without a convincing motive, the scheme loses credibility. The mechanism should not depend on endless author-arranged absences.
The Red-Headed League: pay, hours and attendance conditions. ↗
The Red-Headed League only
The Red-Headed League: Holmes explains the paid distraction and the assistant. ↗
The Red-Headed League only
The copying job's pay attracts Wilson, while its hours and requirement to stay in the office control his absence. The assistant's offer to mind the shop removes a practical objection. Each visible term of the opportunity helps create the same reliable gap in supervision.
Start with the place and uninterrupted time a hidden plan requires. Give its usual occupant a plausible reason to leave and a reassuring arrangement for what they are leaving behind. Write the condition that prevents an early return, then leave a clue linking that condition to the concealed need.
Use in my storyA character takes a warning seriously but protects against the wrong danger. Make the mistaken assumption shape the precautions.
Introduce a capable character with missing memories by showing what they can do before asking what they know about themselves.
Build a mystery around sincere witness statements whose ordinary wording leaves out something crucial.