Tale of test planes mysteriously disappearing and the agent tasked with figuring out why.
Neat combination spy thriller/pseudo science-fiction is almost excellent, marred by a few too many thick-headed bureaucrats, and a climax that is both silly and near unbelievable (and likely the basis for the ending of The Spy Who Loved Me). Richardson is wonderful, though, and it's plain to see that his character was the inspiration for John Steed (as Patrick Macnee has stated). Indeed, this almost seems like a very early prototype for the espionage shows that would be British television's mainstay in the 50s and 60s.