Peter lives with his mother and grandfather in the museum. He knows where to find the most weird and wonderful exhibits and how to open a hundred secret doors. When his grandfather gets sick, Peter decides to search for his father, who disappeared before Peter was born. 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 and wise men aren't wise at all, Peter meets a girl called Festival. She doesn't know where Peter's father has gone, but she might know someone who does. Together they look for the Ancient Child, who has the answers to everything.