First aired: Feb/09/1970
Writer: Kit Pedler, Gerry Davis
Director: Paul Ciapessoni
Guest star: Kevin Stoney (Hal Symmonds), Richardson Morgan (First Engineer), Edward Dentith (Second Engineer), John Lee (Second Captain), Michael Hawkins (Jim Bennett), Tony Sibbald (First Captain), Peter Thompson (Airplane Passenger)

First aired: Feb/16/1970
Writer: Harry Green
Director: Paul Ciapessoni
Guest star: Margaret John (Defending Solicitor)

First aired: Feb/23/1970
Guest star: John Savident (The Minister), Steve Emerson (Lifeboatman), Peter Copley (Tranton)

First aired: Mar/02/1970
Writer: Terence Dudley
Director: Terence Dudley
Guest star: Penelope Lee (Doctor Mary Bryant), Hamilton Dyce (Minister)

First aired: Mar/09/1970
Guest star: Peter Hawkins (Computer Voice), Robert James (Barker), Erik Chitty (Old Man), Nigel Stock (Commander Keeping)

First aired: Mar/16/1970
Guest star: Michael Aspel (BBC Man, Houston), Joseph Fürst (Charles Goldsworthy)

First aired: Mar/23/1970
Writer: Don Shaw
Director: David Sullivan Proudfoot
Guest star: Maurice Roëves (Shipton), William Fox (Scott), John Law (Pegg)

First aired: Apr/06/1970
Writer: Kit Pedler, Gerry Davis
Director: Jonathan Alwyn
Guest star: Sheila Raynor (Mrs. Knott), Aubrey Richards (Bernard Colley), Michael Elwyn (Duncan), Paul Eddington (Reynolds), Edward Kelsey (Captain Gort), Dudley Jones (Doctor O'Brien), Jennifer Daniel (Dana Colley)

First aired: Apr/13/1970
Writer: Terence Dudley
Director: Eric Hills
Guest star: Richard Hurndall (Whitehead), William Lucas (Fielding), George Pravda (Egri), Roy Stewart (Negro)

First aired: Apr/20/1970
Writer: Don Shaw
Director: Vere Lorrimer
Guest star: George Baker (Mitchell), Brian Badcoe (Stephens), William Wilde (Branston), Patricia Maynard (Miss Sephton), Peter Whitaker (Ministry Inspector)

First aired: Apr/27/1970
Guest star: Jeremy Young (Vincent Llewellyn), Emrys Jones (Colonel Smithson), Jay Neill (Laing), Edward Evans (Dai)

First aired: May/04/1970
Guest star: Peter Miles (Cook), Tessa Shaw (Mrs. Reid), Michael Ripper (Reid)

First aired: May/11/1970
Writer: Kit Pedler, Gerry Davis
Director: Hugh David
Guest star: Donald Morley (Air Commodore Parks), Robert Cartland (Commander Sefton), Ray Brooks (Geoff Harker), Hamilton Dyce (Minister), John Dawson (Chief Supt. Charles)

First aired: Dec/14/1970
Writer: Terence Dudley
Director: Terence Dudley
Guest star: Shirley Dixon (Doctor Judith Lennox), Edward Underdown (Chairman of Tribunal), Graham Leaman (Professor Eric Hayland), Donald Morley (Air Commodore Parks)

First aired: Dec/21/1970
Guest star: Peter Welch (Tom Hedley), Sheila Raynor (Mrs. Smith), Geoffrey Palmer (Major Sims), Simon Cain (Soldier), Leslie Meadows (Reggie), Michael Elwyn (Duncan)

First aired: Jan/04/1971
Writer: Louis Marks
Director: Jonathan Alwyn
Guest star: George A. Cooper (Thomas), Shelagh Fraser (Joan), Ian MacKenzie (Islander), George Waring (Busby)

First aired: Jan/11/1971
Writer: Roger Parkes
Director: Darrol Blake
Guest star: Sheila Grant (Gillian Blake), Anthony Ainley (Senior House Officer), Angus MacKay (Professor Lewin), Michael Culver (Minister's PPS), Freda Dowie (Hilda)

First aired: Jan/18/1971
Writer: Robin Chapman
Director: Eric Hills
Guest star: Olaf Pooley (Ensor), Colin Jeavons (Botting)

First aired: Jan/25/1971
Writer: Brian Hayles
Director: Joan Kemp-Welch
Guest star: Frederick Schiller (Mr. Faber), Barry Foster (Doctor Carson), James Maxwell (Doctor Whittaker)

First aired: Feb/01/1971
Guest star: John Quarmby (Secretary), Desmond Llewelyn (Thompson), Michael Elwyn (Duncan)

First aired: Feb/08/1971
Guest star: Michael Elwyn (Duncan), Glyn Owen (Griffiths), Desmond Cullum-Jones (Patterson), Stephanie Bidmead (Janine), John Savident (Minister)

First aired: Feb/15/1971
Director: Lennie Mayne
Guest star: Joseph Greig (Doctor Jackson), David Purcell (Journalist), Simon Lack (Andrew Seaton), Patrick Troughton (McArthur), Alethea Charlton (Flora Seton)

First aired: Feb/22/1971
Writer: Louis Marks
Director: Joan Kemp-Welch
Guest star: Patrick Godfrey (Grant), Ray Armstrong (Donovan), Talfryn Thomas (Hethrington), Philip Bond (Inspector Drew)

First aired: Mar/01/1971
Director: Lennie Mayne
Guest star: Frederick Hall (Pritchard), Judith Furse (Mary Lincoln), George Giles (Policeman), Edward Evans (Coroner), Robert Cawdron (McAlister)

First aired: Mar/15/1971
Writer: Dennis Spooner
Director: David Sullivan Proudfoot
Guest star: Noel Johnson (Priestland), George Selway (C.I.D. Sergeant)

First aired: Mar/22/1971
Guest star: Frances Pidgeon (Secretary), Michael Elwyn (Duncan), Glyn Houston (Gerald Marlowe), Terry Bale (Walsh), Rhoda Lewis (Mrs. Freeman), Roy Purcell (Doctor Barton), Trevor Bannister (Lewis)

First aired: Jun/05/1972
Writer: Terence Dudley
Director: Terence Dudley
Guest star: Clifford Cox (Radio Operator), Talfryn Thomas (Warren), Jonathan Pryce (Police Constable), Michael Elwyn (Duncan)

First aired: Jun/12/1972

First aired: Jun/19/1972
Guest star: Geoffrey Palmer (Chief Supt. Mallory), Paul Seed (Michael), Leslie Schofield (Harry), Elisabeth Sladen (Sarah), Peter Halliday (Rafael)

First aired: Jun/26/1972
Writer: Terence Dudley
Director: Pennant Roberts
Guest star: Frederick Jaeger (Richard Massingham), Don McKillop (Det. Chief Insp. Logan), Margaret John (Mrs. Simpson), Bruce Purchase (Norman Sylvester)

First aired: Jul/03/1972
Guest star: Kenneth Benda (Clive Hughes), Katherine Kath (Lady Holroyd), John Gregg (Roger Halls)

First aired: Jul/10/1972
Guest star: Damon Sanders (Robbie), Michael Hawkins (Beavis), Morris Perry (Professor Hetherington), Barry Jackson (Doctor McEwan)

First aired: Jul/17/1972
Guest star: Cec Linder (Senator Connell), Michael Elwyn (Duncan), Madhav Sharma (Hanif Kahn), Renu Setna (His Excellency)

First aired: Jul/24/1972
Guest star: Michael Keating (Stephen Grigg)

First aired: Jul/31/1972
Guest star: Robert James (G.L.C. Man)

First aired: Aug/01/1972
Writer: Louis Marks
Director: Lennie Mayne
Guest star: Graham Leaman (Wilfred Ridge), John Lee (Doctor Cordell), Nicholas Courtney (Philip)

First aired: Aug/14/1972
Writer: Roy Russell
Director: Darrol Blake
Guest star: Richardson Morgan (Bill Manzaro)

First aired: Unaired
Writer: Stuart Douglass
Director: Darrol Blake
Guest star: Llewellyn Rees (The Rev. Garrison), Brian Wilde (Prof. Fairbairn), Chris Chittell (Dick Burns), Bernard Horsfall (Steven Granger), June Brown (Mrs. Catchpole), Donald Eccles (Lord Purvis)

First aired: Mar/1972
Director: Peter Sasdy
Guest star: Reg Lever (Sam), Norman Bird (Brewer), Cyril Cross (George), James Mellor (First Man), Pam St. Clement (Young Woman), George Woodbridge (Ferry Skipper), Jerome Willis (Lieutenant Commander Tavenar), Ian Bannen (Doctor Del Shaw), Shelagh Fraser (Mrs. Straker), Judy Geeson (Victoria Brown), George Sanders (The Admiral), Paddy Ryan (Grandfather Murray), Katherine Parr (Middle-Aged Woman), Geoffrey Keen (Sir Henry Layton)

First aired: Dec/07/1999
Writer: John Howlett, Ian McDonald
Director: Roy Battersby
Guest star: Wolf Kahler (Director of Ortogene), Christian Rodska (Shashton Driver), Janet Henfrey (Julie), John Vine (Special Branch Officer)