An agent is killed while investigating a small island, and a doctor is abducted after a demonstration of a technique to bring a frog out of hibernation. Steed, Purdey, and Gambit discover the connection is "Germany's Greatest Treasure" and a small island harboring a group of monks.

Felix Kane, a disabled double agent, reactivates the old Cybernaut program so that he can get revenge on the people responsible for his plight: Steed, Gambit, and Purdey.