Maybe Sherlock Holmes would be put in a chamber full of either 1. gas concentrated with so much opium that overexposure could cause overdose...the catch, its foggy and sherlock can't see where the key to get out is in the maze he's been locked in.
Or 2. Sherlock Holmes must get to some opium, but he can't reach it, its past 50 whirling blades he has to manuever around. Sounds like the sort of thing Saw freak would come up with.
EDIT: And what about Watson, what would he be put up against?:P