这部电影是根据英国波特兰间谍案审判的真实事件改编的。一名心怀不满的海军文员被调往一家秘密研究机构，随后遭到勒索
Bernard Lee
Henry Houghton
William Sylvester
Gordon Lonsdale
Margaret Tyzack
Elizabeth Gee
David Kossoff
Peter Kroger
Nancy Nevinson
Helen Kroger
Thorley Walters
Cmdr. Winters
Gillian Lewis
Marjorie Shaw
Newton Blick
P.O. Meadows
Philip Latham
Captain Ray
Cyril Chamberlain
Anderson
Justine Lord
Christina
Patrick Barr
Captain Warner
Derek Francis
Chief Supt. Croft
Hector Ross
Supt. Woods
