Setting: A luxury cruise ship.
Victim: The notorious jewel thief, "Diamond Dan", found dead in his locked cabin.
Clues:
An open window, 20 stories above the water.
A half-eaten plate of chocolate chip cookies.
A locked desk drawer containing blueprints of the ship's ventilation system.
Question:
How did the killer enter and leave the locked room with Diamond Dan dead inside?
Solution:
The killer drugged Diamond Dan with the cookies (laced with sleeping pills). They entered through the ventilation system using the blueprints, accessed through the hidden compartment in the locked drawer. After staging the scene (open window, playing card), they escaped the same way. The locked room was never breached.
Reasoning:
The open window suggests an escape, but the height makes it impossible.
The cookies indicate poisoning, not violence.
The blueprints and ventilation system point to an alternative entry/exit.
