Episode Overview
The investigation begins, with Peter Guillam burgling the archives for information, while Smiley visits an old comrade whose past knowledge could prove vital to locating the spy.
Guest Stars
Bernard Hepton
Toby Esterhase
Ian Richardson
Bill Haydon
Michael Aldridge
Percy Alleline
Terence Rigby
Roy Bland
Beryl Reid
Connie Sachs
Alexander Knox
Control
Frank Moorey
Lauder Strickland
Robert MacNeil
Self – Host (uncredited)