Cast: Donald Houston (David Caulder), Ralph Bates (Michel Lebrun), Fiona Gaunt (Helen Smith), Barry Lowe (Tom Hill), Madhav Sharma (Rao), Michael Lees (Ransome), Michael Wisher (Sanders), Jonathan Sweet (Walters), Peter Bathurst (Director General), Robert La Bassiere (Bill Jackson), Patsy Trench (Jenny), Mary Ann Severne (Sandy), Christine Bradwell (Ingrid), Victor Beaumont (Franz Hauser), Elma Soiron (Madame Carnac)
Written By: Terrance Dicks & Barry Letts
Directed By: Ken Hannam
Ep: 2
Behemoth
Cast: Donald Houston (David Caulder), Ralph Bates (Michel Lebrun), Fiona Gaunt (Helen Smith), Barry Lowe (Tom Hill), John Hallam (Peter Conway), Tom Kempinski (Stephen Partness), Peter Miles (Heinz Laubenthal), Garrick Hagon (Bruno Ponti), Denis DeMarne (Guido Mirandelli), Jurgen Andersen (Per Bengtson), John Moreno (Juan Benavente), Derek Anders (Dr. Andrew Robertson), Robert La Bassiere (Bill Jackson), Anthony Chinn (Cheng), Christine Bradwell (Ingrid), Cy Town (Technician), Ken Howard (Foreman)
Written By: John Brason
Directed By: Ken Hannam
Ep: 3
Achilles Heel
Cast: Donald Houston (David Caulder), Ralph Bates (Michel Lebrun), Fiona Gaunt (Helen Smith), Barry Lowe (Tom Hill), Edward Brayshaw (Adam Blaney), Ann Ridler (Kate Weyman), Malcolm Reynolds (Bill Knight), Nancie Wait (Dodi Knight), Peter Bathurst (Director General), Joanna Ross (Jane), Anne Rosenfeld (Lisa), Oliver Ford-Davies (Astronaut)
Written By: John Lucarotti
Directed By: Christopher Barry
Ep: 4
Outsiders
Cast: Donald Houston (David Caulder), Ralph Bates (Michel Lebrun), Fiona Gaunt (Helen Smith), Barry Lowe (Tom Hill), John Hallam (Peter Conway), Tom Kempinski (Stephen Partness), Madhav Sharma (Rao), John Moreno (Juan Benavente), Garrick Hagon (Bruno Ponti), Victor Beaumont (Franz Hauser), Jonathan Sweet (Walters), Patsy Trench (Jenny), Edmund Pegge (Macadam), Christine Bradwell (Ingrid), Cy Town (Technician)
Written By: John Brason
Directed By: Ken Hannam
Ep: 5
Castor and Pollux
Cast: Donald Houston (David Caulder), Ralph Bates (Michel Lebrun), Fiona Gaunt (Helen Smith), Barry Lowe (Tom Hill), George Pravda (General Trenkin), Milos Kirek (Colonel Gararov), Peter Bathurst (Director General), Madhav Sharma (Rao), Mary Ann Severne (Sandy), Perry Soblosky (Mather), Christine Bradwell (Ingrid)
Written By: John Lucarotti
Directed By: Christopher Barry
Ep: 6
View of a Dead Planet
Cast: Donald Houston (David Caulder), Ralph Bates (Michel Lebrun), Fiona Gaunt (Helen Smith), Barry Lowe (Tom Hill), Michael Gough (Sir Benjamin Dyce), Garrick Hagon (Bruno Bertoli), Magda Miller (Paula Renner), Ed Stewart (Disc Jockey), Robert McBain (Semyonov), Leonard Gregory (Quiz Master), Aubrey Danvers-Walker (Mr. Hopkirk), Anne Rosenfeld (Lisa), Joe Santo (José)