The Doctor and Jo discover the mine's terrible secret. Global Chemicals' managing director, Stevens, is determined that they won't live to reveal what they have learnt.

Jon Culshaw did voice work in Death Comes to Time and The Kingmaker. Culshaw is a member of the Dead Ringers comedy troupe.

Culshaw is renowned for his ability to impersonate the voice of Tom Baker as the Fourth Doctor, a role in which he has made numerous sketch appearances as well as prank telephone calls for Dead Ringers. Among the recipients of Culshaw's prank calls from "the Doctor" were Doctor Who actors Sylvester McCoy, Colin Baker, Peter Davison, and Tom Baker himself. In full makeup as Tom Baker, Culshaw interviewed the real Tom Baker, who had no problem with this imitation at all.

He performed the role of Tom Baker's voicemail in The Five(ish) Doctors Reboot, in which Baker himself did not appear except in archival footage from Shada.

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

Sean Chapman is an English actor. He is best known for playing Frank Cotton in Clive Barker's Hellraiser, and its sequel, Hellbound: Hellraiser II. He is also known for voicing the character Sgt. Michael Sykes (callsigned "Psycho") in Crysis in 2007 and in Crysis Warhead in 2008.

Born on 2 June 1961 in Greenwich, London, England in the United Kingdom, Chapman was abandoned by his father as a child and brought up by his mother. He admits that he was not particularly interested in school, except for English and Drama and, and aged 14, moved to stage school, from where he gained early experience in film and television. At the age of 17 he met the director Alan Clarke, who cast him in his film about Borstal life, Scum. He has since played a variety of roles in British theatre and in both British and European cinema.

His television work is extensive, including leading roles in many single dramas and TV plays, including the films Made in Britain, CH4, and Contact. Sean Chapman is the only actor to have worked three times with Alan Clarke.

Other leading roles in television include The Black and Blue Lamp (BBC), No Further Cause For Concern (BBC), Ellington (ITV), Peak Practice (ITV), Kavannagh QC (ITV), Midsommer Murders (ITV), Trial and Retribution V (ITV), Murphy's Law (ITV). He has also featured in various episodes of French & Saunders and in Absolutely Fabulous. He appeared in the episode 'The Raven in the Foregate' of the third season of Cadfael in 1997 as a medieval murder suspect and spy.

His work in London theatre is also extensive. Leading roles include Enemies (Almeida 2006), A Prayer for My Daughter (Young Vic, 2007).

Leading roles at the National Theatre include Angels in America (1992), Rutherford and Son (1995), Fair Ladies at a Game of Poem Cards (1999), The Prince's Play (2000), Sleep With Me (2002).

His repertory work outside London during the 1980s includes Hamlet (Royal Exchange),Pride and Prejudice (Leicester Haymarket), The Clandestine Marriage (Bristol, Old Vic), Comedy of Errors (York Playhouse), Wolf at the Door, Invisible Friends (Scarborough, Stephen Joseph Theatre).

Other work in London's West End includes the National Theatre production of Single Spies (Queens Theatre), and Me and Mamie O'Rourke (Aldwych).

His first novel, A Distant Prospect, is due for publication in 2010. He is currently completing his second novel, The Blood in the Moon.

_{Biography from the wikipedia article, licensed under CC-BY-SA}

Liam Cunningham is known for a number of films, including First Knight, Dog Soldiers, and Clash of the Titans, and also starred in the BBC Sci-Fi Drama series Outcasts and appearing in Game of Thrones.

Pip Torrens is an English actor.

He was born in Bromley, Kent, England. He studied English Literature at Trinity College, Cambridge. His television appearances includeConsenting Adults, two episodes of Doctor Who ("Human Nature"/"The Family of Blood"), Green Wing,Silk, The Government Inspector (asJohn Scarlett), The Last Detective and DI Torrens for a few episodes in The Bill in 2001. He has also appeared in a 2008 series of UK television advertisements for First Direct, with Matthew King.

In 2011, he appeared in both episodes of an Outnumbered two-part special.

In 2012 he appeared in the first episode of series 8 of Hustle and presented new gameshow The Devil's Dinner Party.

His film appearances include Tomorrow Never Dies as the captain of HMS Bedford, the 2001 film To End All Wars and voicework for Valiant.

He also does work as a simulated patient in medical schools in the UK.

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

Actor who appeared in the 1977 story The Invisible Enemy

Kevork Malikyan (born Diyarbakır, Turkey) is an English character actor of Turkish-Armenian descent, perhaps best known for his role as Kazim in Indiana Jones and the Last Crusade.

He graduated in Surp Haç Armenian High School in İstanbul then moved to London for acting education.

In addition to film work, he has appeared in numerous television productions, including episodes of The Saint, The Professionals, Mind Your Language, Auf Wiedersehen Pet, The Avengers and twice in Minder. He played a number of roles in the RSC production, Arabian Nights (December 2009 - January 2010), at the Courtyard Theatre, Stratford upon Avon.

KHe played Kemel Rudkin in the Doctor Who story The Wheel in Space.

Also appeared in Yozgat Blues, Open Mike, The Palace, James Bond 007: Blood Stone, Silent Witness, 10 Days to War, Saddam's Tribe, Renaissance, Egypt, Flight of the Phoenix, The Predator, Belly of the Beast, Casualty, Judge John Deed, Spooks, Bella Bettien, The American Embassy, In the Beginning, The Commissioner, Into the Blue, Privateer 2: The Darkening, Slave of Dreams, The Final Cut, The Detectives, Paparazzo, Birds of a Feather, MacGyver: Lost Treasure of Atlantis, Minder, The Bill, The Young Indiana Jones Chronicles, The Good Guys, Covert Assassin, Double Vision, Press Gang, Van der Valk, Agatha Christie: Poirot, Zorro, Indiana Jones and the Last Crusade, Pascali's Island, Boon, Half Moon Street, The Corsican Brothers, Scarecrow and Mrs. King, Cold Warrior, The First Olympics: Athens 1896, Duty Free, To Catch a King, Auf Wiedersehen, Pet, Trenchcoat, Crown Court, Peter and Paul, Sphinx, Mind Your Language, The Professionals, Screenplay, The Thief of Baghdad, Midnight Express, Who Pays the Ferryman?, ITV Sunday Night Drama, The Onedin Line, Barlow, Bowler, Little Big Time, The Upper Crusts, New Scotland Yard, Adam Smith, In for a Penny, Jason King, The Man Who Haunted Himself, The Avengers, The Saint, Detective, The Portrait of a Lady

June Bland  is a British actress.

Bland played a leading role in the 1960s British soap, The Newcomers. She also appeared in two Doctor Who serials - Earthshock and Battlefield.

Carmen Silvera  was a Canadian-born British comic actress. Silvera was possibly best known for her starring role in the British television programme, 'Allo 'Allo! as Edith Artois.

She appeared twice in Doctor Who, in the serials The Celestial Toymaker as Clara the Clown, Mrs. Wiggs, and the Queen of Hearts, and as Ruth in Invasion of the Dinosaurs. 

During World War II, Silvera was evacuated to Montreal and narrowly escaped death when, at the last minute, her name was taken off the passenger list of a troopship that was sunk by the enemy shortly afterwards, drowning 350 children. In Canada, she took classes with the Ballet Russes and appeared in three of its productions. On her return to Britain, she felt called to acting and trained at the London Academy of Music and Dramatic Art, before gaining experience in repertory theatre.

Carmen Silvera first made her name as a television actress in the 1960s British police drama Z-Cars in 1962, going on to appear in the BBC soap opera Compact from 1964 to 1965. She played Mrs Van Schuyler in Lillie in 1978, ITV's drama series about the future Edward VII's mistress, Lillie Langtry.

She also appeared in the Dad's Army episode Mum's Army as Fiona Gray, the love-interest for Captain Mainwaring.

She appeared with Ted Rogers at the New Wimbledon Theatrein 1997 in Jimmy Perry's stage musical That's Showbiz. HerWest End stage appearances included roles in Waters of the Moon, starring Ingrid Bergman, Hobson's Choice with Penelope Keith, A Coat of Varnish and School for Wives, which was directed by Peter Hall. She also played a grandmother in the 1997 film La Passione and had roles in Keep It Up Downstairs (1976), Mrs Berkley in On The Game, and in the American film Clinic Exclusive.

In 1990, she was the subject of a This Is Your Life television programme. She did charity work for the Grand Order of Lady Ratlings, the ladies branch of the Grand Order of Water Rats.

Peter Sallis, OBE  is an English actor and entertainer, well known for his work on British television. 

Sallis is best known for his role as the main character Norman Clegg in the long-running British TV comedy Last of the Summer Wine, set in a Yorkshire town. He was the longest serving cast member, appearing in all 295 episodes, and by the end of the show's run was the only one surviving from the programme's first episode in 1973. He also appeared in all 13 of the episodes of the prequel series First of the Summer Wine as Norman Clegg's father. He is also famous for providing the voice of Wallace in the Wallace and Gromit films.

He played Elric Penley in the 1967 Doctor Who serial The Ice Warriors. He was later due to play Striker in Enlightenment but industrial action caused filming times to change and his schedule could no longer fit the role in

Sallis was born on 1 February 1921 in Twickenham, Middlesex, England, the only child of Dorothy Amea (n�e Barnard) and Harry Sallis. After attending Minchenden Grammar School in North London, Sallis went to work in a bank. After the outbreak of World War II he joined the RAF. He failed to get into aircrew because he had a serum albumin disorder and he was told he might black out at high altitudes. He became a wireless mechanic instead and went on to teach radio procedures at RAF Cranwell.

Sallis started as an amateur actor during his four years with the RAF when one of his students offered him the lead in an amateur production. His success in the role caused him to resolve to become an actor after the war, and so he trained at the Royal Academy of Dramatic Arts, making his first professional appearance on the London stage in 1946.

Sallis married Elaine Usher at St John's Wood Church in London on 9 February 1957. Their son, Timothy Crispian Sallis was born in 1959.