After a chance meeting and an indiscreet conversation, childhood friends Tommy Beresford and Tuppence Cowley become involved in a convoluted intrigue led by a mysterious man known simply as Mr. Brown.
Francesca Annis
as Tuppence
James Warwick
as Tommy
Gavan O'Herlihy
as Julius P. Hersheimmer
Alec McCowen
as Sir James Peel Edgerton
Honor Blackman
as Rita Vandemeyer
Peter Barkworth
as Mr. Carter
Toria Fuller
as Jane Finn
John Fraser
as Kramenin
George Baker
as Whittington
Donald Houston
as Boris
Joseph Brady
as Dr. Hall
Wolf Kahler
as The German
