Eleven-year-old Helga Sharp wakes up in a hospital bed on an island, and is told she was found in a boat, her parents missing. She soon learns she is on Utley, a prison island to which the Mainland has exiled troublesome mad scientists for generations, but it's no accident she landed there. Helga made radio contact with Erasmus Lope, a mad genius who everyone thought had died in a lab experiment gone wrong, and she's on a mission to rescue him.