The film is based on the actual events of the Portland Spy Ring trial in the U.K. A disgruntled Navy Clerk is transferred to a secret research establishment and is subsequently black-mailed/paid by Czech intelligence to procure secrets for them. He seduces the secretary who controls the most secret documents, and they enjoy the fruits of their treachery until the British authorities begin to close in on them.
Top Cast
BE
Bernard LeeHenry Houghton
WI
William SylvesterGordon Lonsdale
MA
Margaret TyzackElizabeth Gee
DA
David KossoffPeter Kroger
NA
Nancy NevinsonHelen Kroger
TH
Thorley WaltersCmdr. Winters
GI
Gillian LewisMarjorie Shaw
NE
Newton BlickP.O. Meadows
PH
Philip LathamCaptain Ray
CY
Cyril ChamberlainAnderson
JU
Justine LordChristina
PA
Patrick BarrCaptain Warner
DE
Derek FrancisChief Supt. Croft
HE
Hector RossSupt. Woods
PA
Paul EddingtonJohnnie (uncredited)
RI
Richard MarnerColonel Monat (uncredited)
GE
Geoffrey PalmerPolice Officer (uncredited)
BR
Bryan PringleSurveillance Man (uncredited)
AN
Andre MikhelsonRussian Embassy Official (uncredited)