Top secret information is leaking into Europe from somewhere in Southend and is it a coincidence that Harry Black, a recent escapee from prison, worked in the funfair? Closer examination reveals that the Ghost Train is more scary than it looks and Wickram is arranging the leaks. Trick cigarettes allow Steed to bluff the enemy into submission and Black is proved innocent: he was hypnotised and framed.
* Murray Hayne was originally hired to play Harry Black (and appears in all the known cast lists); he apparently fell ill prior to filming and was replaced by Anthony Bate. (Many thanks to Alan Hayes for uncovering this pearl of wisdom).