First broadcast 25th November 1978.
Years earlier spy Thomas Darby sold out and defected to the Russians. Now he has returned to England.
Gordon Jackson - George Cowley
Martin Shaw - Doyle
Lewis Collins - Bodie
Robert Urquhart - Darby
André Morell - Brig. Stadden
Alan MacNaughtan - Sorenson
Carol Royle - Helen Pierce
George Murcell - Yashinkov
Billy Boyle - O'Leary
Robin Parkinson - Taxi Driver
Shelagh Fraser - Elsa
Myles Hoyle - Lewis
Michael Petrovitch - Callinari
Chris Dillinger - Russian Aide 1
Terence Mountain - Russian Aide 2
Norman Rutherford - Cleric
Lewis Alexander - Commuter
Walter Henry - Cantwell
Aileen Lewis - One of Stadden's Operatives