Finding evidence of alien technology in Smythe's office, the Doctor, Jamie and Zoe make their escape in Lady Jennifer's ambulance, but Smythe gives orders to have them killed.

Sarah is the latest victim of the 'space plague'. But the poison can be removed from her body by transmatting her to the surface of the mysterious planetoid, Voga…

Susannah Harkeris an English film, television, and theatre actor. 

She is the daughter of English actress Polly Adams and actor Richard Owens. She was nominated for a BAFTA TV Award in 1990 for her role as Mattie Storin in House of Cards.

She voiced Clare Keightley in the Web Cast version of Shada.

Harker was also featured in the Big Finish Productions revival of Sapphire & Steel, in which she played Sapphire opposite David Warner as Steel.

Ron Donachie is a Scottish actor. 

He is known for his supporting roles in films The Jungle Book, Titanic and television series Game of Thrones.

He played a steward in the 2006 Doctor Who story Tooth and Claw.

Donachie was born in Dundee, Scotland as Ronald Eaglesham Porter. He was educated at Madras College, St. Andrews and Glasgow University, from where he graduated in English Literature and Drama in 1979.

His brother, Stewart Porter, is also an actor. Donachie is married to Fiona Biggar, they have two children.

Lois Baxter is a British actress, best known for playing Marie Stanton in Coronation Street from 1976 to 1977, and Lady Caroline in the period drama When the Boat Comes In.

Other appearances include: The Black Stuff, Spyder's Web, Within These Walls, Hadleigh, Z-Cars, Doctor Who (in the serial The Androids of Tara), Dickens of London, All Creatures Great and Small, Bergerac, Dempsey & Makepeace, Holby City and The Bill. She has guest-starred in the audio dramas Sapphire and Steel: Cruel Immortality, Circular Time and The Adolescence of Time.

Baxter was born in Bridgwater, Somerset, the daughter of Dr John Baxter and Christine D Baxter (née Arkens). The family later moved to Worthen in Shropshire where John was a General Practitioner for many years. Lois attended Shrewsbury High School from 1951-1959 when she left for boarding school.

Harry Fielder (sometimes credited as Harry Aitch Fielder) (born in Islington,London) is an English actor and supporting artist who has worked extensively in British films and television since the 1960s.

Despite being based entirely in Britain, Fielder has appeared in a large number of American films, due to filming taking place partly or entirely in Britain. His film credits include Star Wars: A New Hope, McVicar, Highlander andOliver!.

Fielder has appeared in a wide range of TV shows including Doctor Who, Blake's 7,Shoestring, The Sweeney, Minder and The Professionals.

Fielder co-presented CBTV, a Thames TVprogramme for younger viewers, in the 1980s where he played the Security Guard, Harry, who Jim Sweeney and Steve Steen would have to sneak past on the gates of Teddington Studios.

Biography from the Wikipedia article, licensed under CC-BY-SA

Gareth Gwenlan is a British television producer, best known for his work on shows such as The Fall and Rise of Reginald Perrin, To the Manor Born, Only Fools and Horses, and High Hopes. 

He was Assistant Floor Manager for the Doctor Who stories The Savages and The Underwater Menace, and Production Assistant for The Web of Fear.

In 1983 he was appointed Head of Comedy for BBC.

Graham Ashley played the Overseer in the 1967 Doctor Who story The Underwater Menace.

He was well know on British television appearing in early series's of Grange Hill.  He later played Gold Five in Episode IV of Star Wars.

Worked on Grange Hill, Licensed to Love and Kill, Some Mothers Do 'Ave 'Em, Scorpion Tales, Z Cars, Play for Today, Somebody's Daughter, Adventures of a Plumber's Mate, The Black Panther, It Could Happen to You, Star Wars: Episode IV - A New Hope, Adventures of a Private Eye, Holding On, The Deadly Females, Hunter's Walk, Mr. Smith, Angels, Adventures of a Taxi Driver, Alfie Darling, Porridge, Hennessy, Six Days of Justice, Churchill's People, Eskimo Nell, The Carnforth Practice, Bedtime Stories, The Protectors, Dixon of Dock Green, Billy Liar, Our Cissy, The Swordsman, Big Zapper, Softly Softly: Task Force, Colditz, The Fast Kill, Steptoe and Son, Manhunt, Strange Report, Doctor in the House, The Power Game, The Avengers, No Hiding Place, Danger Man, The Edgar Wallace Mystery Theatre, Crossroads, ITV Play of the Week, Dr. Finlay's Casebook, Taxi!, Suspense, The Young Detectives, The Last Man Out, BBC Sunday-Night Play, The Cheaters, The Tell-Tale Heart, Man Accused, The Infamous John Friend, A Christmas Night with the Stars, Kenilworth, Stryker of the Yard, London Playhouse, Track the Man Down, The Pickwick Papers, BBC Sunday-Night Theatre

Derek Waring started playing DI Neil Goss in 1969, in the police drama Z-Cars and continued in this role for 215 episodes until 1973. Following Z-Cars he played Roland Moody in Moody and Pegg. Later in the 1970s, Waring appeared in programmes such as Murder Most English, Crown Court, The New Avengers, Two's Company and George and Mildred. In 1980, he played Harry Somers in the Scottish soap opera Take the High Road. During the 1980s he appeared on screen in The Enigma Files, Never the Twain and The Professionals. In 1982, he appeared as Shardovan in the third and fourth parts of the Doctor Who serial "Castrovalva".

He was a member of the Royal Shakespeare Company and appeared in many productions including War of the Roses.[3] In the West End he appeared in Cowardy Custard, Suzie Wong and in the late 1980s The Boy Friend, which was his final West End appearance. On Broadway he played Prince Albert in Portrait of a Queen[2] opposite his wife who played Queen Victoria.

His father was the TV pioneer Wing Commander H.J. Barton-Chapple, who had worked with John Logie Baird.

Donald Eccles  was a British character actor.

Eccles was born in Nafferton, Yorkshire the son of Charles Henry and Constance Eccles, his father was doctor. Eccles was educated at Highgate School and then worked in an insurance office.

He made his stage debut in New York City in 1930, and later became known as a member of the Royal Shakespeare Company. His debut in London was in Counsellor at Law in 1934 at the Picadilly. During the second world war he spent six years in the navy.

In 1960, he appeared in his first film, A Taste of Money, and continued to appear in small roles in film and television (such as Mr Justice Vosper in the second series of Rumpole of the Bailey) until his death, in a road accident, in Brighton.

He played Krasis in the Doctor Who story The Time Monster.

He worked on Blood Royal: William the Conqueror, Paradise Postponed, The Theban Plays by Sophocles, The Return of the Antelope, Never the Twain, Silas Marner: The Weaver of Raveloe, Young Sherlock Holmes, Oliver Twist, Shine on Harvey Moon, A Private Function, Don't Wait Up, Fresh Fields, The Master of Ballantrae, Crown Court, Minder, The Dresser, Tom, Dick and Harriet, Tales of the Unexpected, Coming Out of the Ice, The Hunchback of Notre Dame, Brideshead Revisited, Play for Today, Ladykillers, A Question of Guilt, Quatermass, The Legend of King Arthur, ITV Playhouse, Rumpole of the Bailey, People Like Us, Supernatural, I, Claudius, Lorna Doone, Killers, ITV Sunday Night Drama, The Prince and the Pauper, You're on Your Own, Public Eye, Microbes and Men, Marked Personal, The Nine Tailors, Special Branch, The Fortunes of Nigel, The Pallisers, Great Mysteries, Pianorama, The Wicker Man, The Protector, The Upper Crusts, Country Matters, Emma, ITV Sunday Night Theatre, The Shadow of the Tower, The Adventurer, Softly Softly: Task Force, BBC Play of the Month, Fraud Squad, Doomwatch, The Caesars, The Devil in the Fog, A Midsummer Night's Dream, The Revenue Men, Champion House, Thirty-Minute Theatre, Write a Play, Adam Adamant Lives!, The Gamblers, Theatre 625, Love Story, The Wednesday Play, Macbeth, Knock on Any Door, The Mask of Janus, Front Page Story

Ann Davies played Jenny in the The Dalek Invasion of Earth.

In the documentary Future Memories, Davies claimed that Jenny was under consideration as a replacement companion following the departure of Susan Foreman at the end of the episode. Davies also noted that she became friends and neighbours with actress Jacqueline Hill. This recollection incorrectly suggested that perhaps Davies was, like Pauline Collins, a "companion-that-almost-was".

However, it was only Jenny that was considered as a replacement, not Davies herself. The extensive notes left behind of this period of Doctor Who's history clearly indicate that the character was originally called "Saida" and had been offered first to Pamela Franklin on about 17 August 1964. Lambert had made this offer because BBC1 Controller Donald Baverstock had agreed to renew Doctor Who for thirteen weeks beyond the end of Carole Ann Ford's contract, which lasted until the conclusion of Dalek Invasion.

Almost as soon as he had agreed to the extension, however, Baverstock withdrew the offer as a ploy in the renegotiation of William Hartnell, Hill and William Russell's contracts. In the waning days of August, 1964, Verity Lambert was forced to consider that the whole show might end at the conclusion of the present production block. Indeed, Baverstock flatly told her on 19 August 1964 that "it would be unwise to establish the new girl as a permanent member of the cast in the last episode" of Dalek Invasion and even suggested that if the salary negotiations failed, "a totally new or partly new group of principals" might have to be considered. Lambert therefore reversed herself and ordered Jenny be written as a one-shot guest. The deal with Franklin fell through and the now-smaller role was subsequently offered to Davies.

It therefore seems extremely unlikely that she would have ever believed herself actually in the running for a regular part on the programme, because by the time the part was actually offered her it was firmly that of a secondary guest character.

She was married to Richard Briers from 1956 until his death in 2013.

Biography from the TARDIS Data Core article, licensed under CC-BY-SA

Costume Designer on several Tom Baker episodes.

He died after a prolonged battle with MS, and is survived by his wife Norma.

Michael Coles played Ganatus the 1965 film in Dr. Who and the Daleks.

Barry Gray composed the music for the Dalek movies produced in the 1960s and starring Peter Cushing as Dr. Who. Gray is best known for his work composing themes and incidental music for Gerry Anderson's numerous Supermarionation and live-action series, including Stingray, Thunderbirds, Captain Scarlet and the Mysterons, UFO, and the first season of Space: 1999.

Kevin Lindsay was an Australian actor, based in Britain.

He appeared as Cho-Je in Planet of the Spiders as well as playing the first Sontaran to be seen in the series in The Time Warrior. Later he played two more members of this species inThe Sontaran Experiment.

He died from a heart condition.