Elevator to Nowhere (Give Yourself Goosebumps, No 34)

You've got a science project to do-boring-but your friend is sure you're going to win the prize for the best project because he's invited you over to his uncle's house. Thing is, though his uncle is an inventor he's also a super-weirdo, and he wants to try out his experiments-on you! Better get out fast. But it looks like your only escape is the elevator-the one that takes you to alternative universes, where everyone seems to be insane and-uh-oh-out to get you!