- Brian Wilde - George Horton
- Brian Wilde - Dr. Boddington
- Michael Robbins - C.P.O. Bradshaw
- Neil Stacy - Seaman Giuseppe Fabbri
- Terence Alexander - Paul Paragon
- Trevor Bannister - Martin Fowler
- Peter Wyngarde - Paul Panacek
- Warren Mitchell - Petropolous
- Edward Chapman - Oliver Crawford
- Lyndon Brook - Alan Haynes
- George Sewell - Shelton
- Derek Fowlds - Bruce
- Danny Green - 'Kipper' Da Vinci
- Vladek Sheybal - Yasha Saroya
- Vladek Sheybal - Max Opals
- Geoffrey Palmer - Ian McWatt
- Roy Marsden - Lt. David Stanton
- John Comer - Sgt. Thomas Lynch
- John Quayle - Lt. Julian Goltheart
- Geoffrey Keen - Robert Grimes
- Anthony Newlands - Sir Graham Brome
- Julie Goodyear - Duckie
- John Stratton - Leonard Fitch
- Mike Pratt - Jack Simpson
- Mike Pratt - Lt. Manuel Rafael Achara
- Leonard Sachs - General René Gavreau
- Nicholas Courtney - Gilles
- Jerome Willis - Guy Leduc
- Adrienne Corri - Lynne Crawshaw
- David Langton - George Henderson
- Roger Hammond - Bannerman
- Meg Wynn Owen - Glynis Hughes
- Dinsdale Landen - Peter Nash
- Barbara Jefford - Ursula Dallendorf
- Hugh Burden - Charles Morrow
- Christopher Benjamin - Chief Supt. Craythorpe
- David Horne - Lord John Bower
- Michael Gough - Andrei Konev
- Colin Jeavons - Dr. Jim Pearson
- Rio Fanning - John Corry
- Eric Thompson - Manuel
- Ian Ogilvy - Pedro Da Silva
- Anthony Hopkins - Dr. Harding
- Barry Linehan - Lampeter
- Carol Cleveland - Marya Ference
- Jill Dixon - Moira Leigh
- Frank Thornton - Chief Inspector Bascombe
- Donald Pickering - Hatier
- Dilys Laye - Karen
- Barbara Knox - Barbara Mullaney
- Jan Waters - Juliet Severne
- Scott Forbes - Major Cody Myers
- Denis Quilley - Huston
- Tony Steedman - James Hardacre
- David Neal - Walker
- Jameson Clark - Inspector Mainwaring
Anthony Hopkins interpreta a Dr. Harding en la serie.
Michael Gough interpreta a Andrei Konev en la serie.
Adrienne Corri hace el papel de Lynne Crawshaw.
Richard Vernon interpreta a Oldenshaw en la serie.
Denholm Elliott interpreta a Imlac Defraits en la serie.
Capítulo disponible en las siguientes plataformas:
