The Last of the Cybernauts ...??

When a double agent called Kane is horribly disfigured in a chase, he vows vengeance...and calls upon the powers of a force who has tangled with Steed and his associates twice before: the Cybernauts. Creations of a misguided and imbalanced scientist, Dr Armstrong, these metallic menaces in both their attempts were stopped by the suave Steed and the inimitable Mrs Peel. However, this time they are being manipulated by an even more malignant force, and Steed and his friends enter into great danger in an attempt to stop the Cybernauts one last time.

Steed fête son anniversaire lorsque Terry, un vieil ami, arrive, mourrant, chez lui et révèle qu'il a trouvé l'agent double : Felix Kane et qu'il a rendez-vous le lendemain avec son contact.