This synopsis is based upon the Big Finish audio adaptation of the original television script. The original episode’s master tape is lost and presumed destroyed. This audio adaptation can be found in Volume 1 of Big Finish’s The Avengers: The Lost Episodes series.
Steed is involved in an operation to keep a major medical secret out of the wrong hands. A drug that temporarily presents the appearance of a cure (but allows a disease to continue doing damage to its victim) could be a powerful weapon in the hands of an assassin, and Steed and his superiors mean to keep it from being misused. Steed enlists the help of Dr. Keel, who already has an invitation to the World Health Organization in Geneva, to deliver the drug’s chemical formula to an ally within the WHO. But almost immediately, things go wrong: Keel is targeted and followed before he even leaves British soil. Steed must follow Keel to Geneva in order to keep his friend and ally from coming to a grim end (and to ensure the safety of the free world into the bargain).
written by Brian Clemens
directed by Peter Hammond
music by Johnny Dankworth
Big Finish audio adaptation written by John Dorney
Big Finish audio adaptation directed by Ken Bentley
Big Finish audio adaptation music by Toby Hrycek-Robinson
Original television cast: Ian Hendry (Dr. Keel), Patrick Macnee (John Steed), Ingrid Hafner (Carol Wilson), Ronald Wilson (Scott), Malou Pantera (Yvette), Dennis Edwards (Pallaine), Peter Madden (Benson), Irene Bradshaw (Maid), Frank Gatliff (Dubois), Steven Scott (Hotel Concierge), Toke Townley (Bernard Bourg)
Big Finish audio cast: Anthony Howell (Dr. Keel), Julian Wadham (John Steed), Lucy Briggs-Owen (Carol Wilson), Sam Clemens (Wilson), Francesca Hunt (Yvette), Nigel Carrington (Pallaine), Nicholas Briggs (Benson), Terry Molloy (Henry)
LogBook entry by Earl Green