A young boy, Kay Harker, comes into contact with a magical box, which allows him to shrink in size, fly swiftly, travel into the past, and experience the magical wonders within the box itself. He takes custody of the box from an old Punch-and Judy man, Cole Hawlings, and must protect the box from the villains who want it for themselves.
John Masefield's novel, one of his best-known works, was adapted by Australian playwright Alan Seymour during the latter's long period of work for the BBC.