Peter lives with his mother and grandfather in the museum, which has the most weird and wonderful exhibits and a hundred secret doors. When his grandfather gets sick, Peter decides to search for his long-lost father. Instead, he finds a strange old woman who gives him a book called How To Live Forever but makes him promise never to read it.

Trapped in a world where books are houses, Peter meets a girl called Festival, and together they look for the Ancient Child, who has the answers to everything.