The story begins in contemporary London, where Mig and Chris live with their mother Betty Laker. Their father has left with another woman, then disappeared in an automobile accident on the way to visit his Aunt Maria. Betty Laker, responding to Aunt Maria's plea to spend Easter vacation with her in distant Cranbury-on-Sea, takes Mig and Chris and goes to the shore. On arriving, Mig and Chris discover a magical, dreary community ruled mysteriously by Aunt Maria. The townswomen are her co-conspirators, the men behave like zombies, and the children appear to be clonelike orphans.