I was thinking...

One way to make things even worse for a person who was being kept as a prisoner in an empty room at the top of the highest tower of an old castle, would be to give them a slinky. The knowledge that outside the locked door of their cell was a seemingly endless spiral staircase just sitting there with no one using it and the fact that the only thing they had in their room was a slinky, that would be perfect to play with on those stairs, would slowly drive them insane. Then they would probably get the idea to jump out of the window while holding onto to one end of the slinky while the other end of the slinky was attached to a bed post. They would hope that it would bare their weight and slowly lower them to the ground like a bungee cord, but it wouldn't and they would most likely end up in the castle moat surrounded by hungry alligators. 

Just a thought.