To free Houdini from his cell you’ll have to discover the tools and work out how to use them. One feature that Brian builds into many of these types of sequential discovery puzzles is to give you something to find almost immediately; better to maintain interest in the puzzle. You’ll find that with this puzzle too. Yes, there are lots of magnets in the puzzle but no “hitting” or “banging” is necessary to solve it. There is a tool to discover for every aspect of the solve.
The idea for Houdini’s Torture Cell came from one of the locks in the incredibly complex The Opening Bat puzzle (part of the Sold Out Limited Edition 2010 series). Brian felt the idea was unique and very satisfying to solve so he revisited the idea and made a separate puzzle. Unlike The Opening Bat where the puzzle was completely hidden inside, this puzzle has been presented in such a way that most elements of the puzzle are visible to you. The puzzle is to then work out how to use those tools to solve it. You can literally sit and think about the solution without even touching the puzzle.