Synopsis by Hal Erickson
Under his cloak of invisibility, Peter Brady quietly investigates the possibility that Uranium-235 is being smuggled into Great Britain for the purpose of triggering an atomic war. Making Brady's task difficult is the presence of famed pacifist leader Waring (William Squire), who has been duped into helping the villains booby-trap the major capitals of the world. Edward Hardwicke, the son of Sir Cedric Hardwicke and the later "Dr. Watson" to Jeremy Brett's Sherlock Holmes, appears in a featured role. This final episode of The Invisible Man was cowritten by The Avengers' Brian Clemens, pseudonymously billed as Tony O'Grady.