American pilot Lieutenant Tak Pendleton takes part in an experiment in which he is shrunk to a very small size and, in a submarine-like craft, explores the inside of a rabbit. But techno-terrorists ruin all plans and steal the syringe containing the miniature Tak. By mistake, the contents of the syringe end up in the body of hypochondriac Jack Patter. Now the terrorists begin hunting for the unsuspecting Jack. The only one who can help him is Tak’s girlfriend, journalist Lydia.