The travellers find themselves deep below the Earth's surface, in the lost city of Atlantis. The Doctor meets the mad Professor Zaroff and Polly is to be turned into a fish person.

Jemma Redgrave is a fourth-generation English actress of the Redgrave family.

Born in London, she is the daughter of the late actor Corin Redgrave and his first wife, the late Deirdre Hamilton-Hill, a former fashion model. She trained at the London Academy of Music and Dramatic Art.

Redgrave has appeared in many roles on British television and is best known for her portrayals as Eve Granger in Cold Blood, Dr. Eleanor Bramwell in Bramwell, Eleanor in The Buddha of Suburbia, Francesca Rochester in Judge John Deed, and Dee Stanton in Like Father, Like Son. In 2007, she portrayed the indolent Lady Bertram in Mansfield Park, and Sophie Wall in Waking the Dead.

Her film roles include Evie Wilcox in Howards End and Daisie in Lassie in 2005. She has had a long stage career

Adjoa Andoh  is a British film, television, stage and radio actress of Ghanaian descent. 

Andoh is known on the UK stage for lead roles at the RSC, the National Theatre, the Royal Court Theatre and the Almeida Theatre, and is a familiar face on British television (notably in two series of Doctor Who as companion Martha's mother Francine Jones, 90 episodes of the BBC's long-running medical drama Casualty as Sister Collette Griffiths and a year in the BBC's EastEnders). 

Andoh is the voice of Alexander McCall Smith's No. 1 Ladies Detective Agency; she won Audio Book Of The Year for Tea Time for the Traditionally Built.

he made her Hollywood debut in Autumn 2009 starring as Nelson Mandela's Chief of Staff Brenda Mazikubo alongside Morgan Freeman as Mandela in Clint Eastwood's Invictus.

She is married to the author/lecture Howard Cunnell and have two children; Andoh is a licensed Reader.

Suzanne Danielle played Agella in the 1979 Doctor Who story Destiny of the Daleks. 

She is best known for playing the lead role in 1978's Carry On Emmannuelle, the final film in the original Carry on... series.

Also worked on 2 Female Spies with Flowered Panties, Escape from El Diablo, Jim Davidson's Special, Strangers, Jane, Tales of the Unexpected, Mike Yarwood in Persons, The Boys in Blue, Mike Yarwood in Persons, Hammer House of Horror, Sir Henry at Rawlinson End, The Morecambe & Wise Show, Flash Gordon, Arabian Adventure, The Golden Lady, Long Shot, The Stud, The Wild Geese, The Professionals

Spencer Chapman was Designer for The Dalek Invasion of Earth and The Space Museum.

Also worked on In Love with Alma Cogan, Gilbert & Sullivan: A Motley Pair, She Stoops to Conquer, Falstaff, A Mind to Murder, Unnatural Causes, Devices and Desires, Anything More Would Be Greedy, A Taste for Death, Tales of the Unexpected, A Killing on the Exchange, The Black Tower, Love Song, The Kingfisher, Private Schulz, God's Wonderful Railway, Shoestring, Play for Today, BBC Play of the Month, The Glittering Prizes, Centre Play, Late Call, Dr. Watson and the Darkwater Hall Mystery, The Edwardians, The Sextet, The Golden Bowl, Clochemerle, Roads to Freedom, The First Churchills, The Expert, The Wednesday Play, The Jazz Age, Detective, Vanity Fair, The Forsyte Saga, The Spies, An Enemy of the State, The Mask of Janus, Theatre 625, First Night, Z Cars

Richard Briers, CBE  was an English actor whose career has encompassed theatre, television, film and radio.

He was best known for the number of British sitcoms he has starred in, with his best known role being that of  Tom Good in the BBC seriesThe Good Life.

He played The Caretaker in the 1987 Doctor Who story Paradise Towers.

Briers was born in Raynes Park, Surrey, England, the son of Joseph Benjamin Briers and Morna Phyllis (n�e Richardson). He is the second cousin of actor Terry-Thomas.

He spent his childhood in Raynes Park and Guildford. He attended Rokeby Prep School in Wimbledon, and left at the age of 16 without any formal qualifications. His first job was a clerical post with a London cable manufacturer, and for a short time he went to evening class to qualify in electrical engineering, but soon left and became a filing clerk.

At the age of 18, he was called up for two years National Service in the RAF, during which he was a filing clerk at RAF Northwood, where he met future George and Mildred actor Brian Murphy. Murphy introduced Briers, who had been interested in acting since the age of 14, to the Dramatic Society at the Borough Polytechnic Institute, now London South Bank University, where he performed in several productions.

When he left the RAF he studied at RADA, which he attended from 1954 to 1956. He won a scholarship with Liverpool Repertory Company, and he worked with them for 15 months, then moved to the Belgrade Theatre in Coventry for 6 months and then had his West End debut.It was while at Liverpool Rep that he met his future wife Ann Davies, who was acting as stage manager, and has acted on television since the 1960s.

Briers gained the lead male role in Marriage Lines (1961�66) opposite Prunella Scales (he was the godfather to her son Sam). The following year Briers appeared in Brothers in Law (from the book by Henry Cecil) as callow barrister Roger Thursby. He was cast in this role by adaptors Frank Muir and Denis Norden, who had seen him in the West End. His other early appearances included Dixon of Dock Green (1962), The Morecambe & Wise Show, The Seven Faces of Jim (1961) with Jimmy Edwards, a production of No�l Coward's Hay Fever (1968) and the storyteller in several episodes of Jackanory (1969).

Briers was cast in the lead role in The Good Life (1975�78), playing Tom Good, a draughtsman who decides, on his 40th birthday, to give up his job and try his hand at self-sufficiency. An enormously successful series, the last episode in 1978 was performed in front of the Queen. In 1977, he starred with his The Good Life co-star Penelope Keith in the televised version of Alan Ayckbourn's trilogy The Norman Conquests.Briers was the original narrator and voice actor for the Enid Blyton series Noddy.

During the 1980s and 1990s, he played roles in many programmes including Goodbye, Mr Kent (1982), All in Good Faith (1985), Tales of the Unexpected (1988), Mr. Bean (1990) and Twelfth Night (1988) as Malvolio. From 1984 to 1989 he was the lead role of Martin Bryce in Ever Decreasing Circles, and in 1993 took the lead role of Godfrey Spry in the BBC comedy drama If You See God, Tell Him. In 1995 he played the character Tony Fairfax in the BBC comedy 'Down to Earth' Tony Fairfax (Richard Briers) plays a cultural adviser to the President of a banana republic in Latin America. When the President is deposed by a military coup, Tony is sacked and deported back to England and ends up staying with his brother Chris (Christopher Blake) and his wife Molly (Kirsten Cooke).

Briers has spent much of his career in theatre work, including appearances in plays by Shakespeare and George Bernard Shaw. In 1967, one of his earliest successes was playing alongside Michael Hordern and Celia Johnson in the London production of Alan Ayckbourn's Relatively Speaking. Briers was a member of Kenneth Branagh's Renaissance Theatre Company, taking on classical and Shakespearean roles including Malvolio in Twelfth Night and the title roles in King Lear and Uncle Vanya. Briers has also appeared in nine of Kenneth Branagh's films, such as Henry V (as Bardolph, 1989), Much Ado About Nothing (as Signor Leonato, 1993), and as Polonius in Hamlet (1996).Briers is also a familiar voice actor, with numerous commercials, including adverts for the Midland Bank in which he was the voice of the company's Griffin symbol, and the animated children's series Roobarb (1974), Noah and Nelly in... SkylArk (1976) and Bob the Builder (2005) to his credit. He also provided the voice of Fiver in the animated film adaptation of Watership Down (1978).Between 1984 and 1986 he made a series of commercials for the Ford Sierra done in a sitcom style portraing the Sierra as "one of the family".His work in radio includes playing Bertie Wooster in a series of adaptations of the Jeeves novels by P. G. Wodehouse, Dr. Simon Sparrow in BBC Radio 4's adaptions of Richard Gordon's Doctor in the House and Doctor At Large (1968) (currently repeated on BBC Radio 4 Extra), a retired thespian in a series of six plays with Stanley Baxter Two Pipe Problems, and later the play Not Talking, commissioned for BBC Radio 3 by Mike Bartlett.

Since 1990, he has appeared in Lovejoy, Inspector Morse, Midsomer Murders (the episode "Death's Shadow"), Doctors, New Tricks, Kingdom, and If You See God, Tell Him. Richard Briers starred as Hector in the first three series of Monarch of the Glen from 2000 to 2002, a role which saw him return to the limelight. He contributed "Sonnet 55" to the 2002 compilation album, When Love Speaks, which features famous actors and musicians interpreting Shakespeare's sonnets and play excerpts. In 2005, he appeared alongside Kevin Whately in Dad, a TV Film made by BBC Wales exploring issues of elder abuse. In 2006, he made an appearance in an episode of Extras, and portrayed the servant Adam in Kenneth Branagh's 2006 Shakespeare adaptation, As You Like It. He made a cameo appearance as a dying recluse in the 2008 Torchwood episode "A Day in the Death".

Richard Briers was appointed OBE in 1989, and CBE in 2003.

As a result of Terry-Thomas's Parkinson's disease, Briers became President of the Parkinson's Disease Society. Richard Briers is also a non-medical patron of the TOFS (Tracheo-Oesophageal Fistula Support) charity, which supports children and the families of children born unable to swallow.

The actor passed away peacefully at home on the 17th February 2013 after battling a lung condition. 

Peter Barkworth was an English actor.

He played Leader Clent in The Ice Warriors

He is best remembered for playing Mark Telford in the TV series Telford's Change. This series followed the life of a senior banking executive as he downsized to Dover to start his life over again.

Barkworth won a BAFTA for his roles in Professional Foul and The Country Party (both 1977). Barkworth also played the expatriate British novelist Hugh Neville in the episodes Guilt and Lost Sheep of Secret Army (1977). 

Later TV included the part of Stanley Baldwin in Winston Churchill: The Wilderness Years (1981), and the serials The Price (1985) and Late Starter (also 1985)

Barkworth appeared in numerous plays in the West End, notably as Edward VIII in Royce Ryton's Crown Matrimonial starring alongside Wendy Hiller at the Haymarket Theatre in 1972, a role which he repeated on TV two years later. He also devised a one-man show based on the work of Siegfried Sassoon.

His film career began in 1951 with A Touch of Larceny. He had subsequent roles in Where Eagles Dare (1968), Patton (1970) and International Velvet (1978). His last appearance was in the film Wilde in 1997. 

Barkworth was a member of the Council at RADA for 16 years during the 1980s and 1990s. His book About Acting – formerly titled The Complete About Acting – is often recommended reading for students and professional actors alike.

Donald Gee  appeared in two Doctor Who stories: as Major Ian Warne in The Space Pirates and Eckersley in The Monster of Peladon.

He was born in Stockport, Cheshire.

Other roles include Born and Bred, Casualty, Killing Me Softly, Midsomer Murders, Doctors, Chambers, Lady Audley's Secret, The Bill, Vigo: A Passion for Life, Trial & Retribution, Oh Doctor Beeching!, The Girl, Coronation Street, Boon, Wish Me Luck, Screen Two, Tears in the Rain, The Queen's Arms, Summer Season, Late Starter, Driving Ambition, Play for Today, Yes Minister, Play for Tomorrow, BBC2 Playhouse, The Olympian Way, Timon of Athens, The Rear Column, A Family Affair, Z Cars, One-Upmanship, 1990, Van der Valk, A Roof Over My Head, Mr. Big, On the Move, Against the Crowd, BBC Play of the Month, Churchill's People, Fall of Eagles, If There Weren't Any Blacks You'd Have to Invent Them, Soap Opera in Stockwell, Black and Blue, Great Mysteries, Ooh La La!, Thriller, Whatever Happened to the Likely Lads?, The Silver Sword, Unman, Wittering and Zigo, ITV Sunday Night Theatre, The Expert, The Wednesday Play, Detective, Thirty-Minute Theatre, Journey to the Unknown, The Avengers, The Bofors Gun, Theatre 625 , Dixon of Dock Green, Journey to Midnight, The Fellows, The Forsyte Saga, The Troubleshooters, The Likely Lads, Ferry Cross the Mersey

Robert Banks Stewart is a Scottish writer for television in the UK, who was sometimes credited as Robert Stewart early in his career. Banks Stewart contributed extensively to drama for the BBC and ITV for several decades.

Born in Edinburgh, he began writing as a journalist, working for the city's evening newspapers, where he became the youngest news editor in history for the Evening Dispatch. Even then, he used to discuss ideas for television series. Later he became a story editor at Pinewood Studios. Working as a scriptwriter from the end of the 1950s, he worked on such TV series as Danger Man, The Human Jungle, Top Secret and The Avengers ("The Master Minds" and "Quick-Quick Slow Death"). He also contributed a few scripts to the Edgar Wallace Mysteries series of second-features for the cinema.

Working for Thames Television he contributed scripts to the programmes Callan, Special Branch, The Sweeney and Owner Occupied. For HTV, he wrote 5 episodes of Arthur of the Britons. Banks Stewart wrote two highly regarded serials for the BBC science-fiction series Doctor Who: Terror of the Zygons (1975) (which was set in his native Scotland and drew on the Loch Ness Monster legend) and The Seeds of Doom (1976) (which was influenced by classic science-fiction such as The Day of the Triffids, The Quatermass Experiment and The Thing from Another World).

Banks Stewart continued working in television as a writer, script editor and producer, creating Shoestring (1979–80), which ran for two series on the BBC and following this up with the Jersey set detective drama series Bergerac (1981–89). He later produced Hannay (5 episodes, 1988), The Darling Buds of May (4 episodes), Lovejoy (10 episodes) and Call Me Mister. His final credit for television was for the adaptation of My Uncle Silas (2001–03) starring Albert Finney.

At the age of 81, Banks Stewart published his first novel – a thriller entitled The Hurricane's Tail, featuring a British detective called Detective Sergeant Harper Buchanan who uncovers a political plot against the prime minister of a Caribbean island. It was originally envisaged as a two-part TV series, but Banks Stewart said he decided to turn it into a novel after "getting nowhere" with TV executives, which he attributed to ageism.

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

Appeared in the 1964 story The Sensorites.

Mark Jones  was a British actor, who appeared frequently in various television series.

Credits include: A Family at War, Z Cars, Van der Valk, Doctor Who (in the serial The Seeds of Doom), The New Avengers, The Onedin Line, Target, Secret Army, Tales of the Unexpected, Buccaneer, Blott on the Landscape, Casualty, Call Me Mister and Dempsey & Makepeace.

He also appeared in the Star Wars saga film The Empire Strikes Back.

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

Jack Kine was a visual effects designer for the 1968 Doctor Who television story The Mind Robber. He was also seen, uncredited, as "the Leader" in the second episode of Inferno.

Kline was the co-founder in 1954 of the BBC Visual Effects Department along with Bernard Wilkie, he worked on many landmark productions, inventing techniques that stood the burgeoning industry in good stead for decades to come. 

Their baptism of fire was 'Running Wild' with Morecambe and Wise in 1954, quickly followed by Rudolph Cartier's epic production '1984'. They learnt fast and quickly: on 'Quatermass II' (1955) the amorphous monster was hurriedly put together after Cartier finished one morning session with the announcement that "after lunch we shoot the creature". 

Although shows were predominantly live, some pre-filming was allowed for 'Quatermass and the Pit' (1958/59), for which Kine designed the hideously plausible Martian creatures. 

Their remit covered every genre including comedy (Dad's Army, Some Mothers Do 'Ave 'Em), drama (Z-Cars, Maigret) and education (Blue Peter and Tomorrow's World). They weren't backroom boffins, but an integral part of the studio team, establishing a rapport with cast and crew alike. 

The television Visual Effects Department became the biggest of its kind in the world, with a bevy of talented designers blowing things up with aplomb. BBC bureaucracy would not allow joint heads of department, so Kine became the titular chief, assuming a more administrative role, whilst Wilkie continued on the workshop floor. 

Kine worked on the realisation of the original TARDIS as well as the Daleks.

John Witty voiced the computer in the Doctor Who story The Seeds of Death.

Also appeared in Q9, Some Mothers Do 'Ave 'Em, The Vault of Horror, Out of the Unknown, The Dick Emery Show, Curse of the Voodoo, The Cheaters, The Frightened City, Dial 999, Moment of Indiscretion, Dixon of Dock Green, The New Adventures of Charlie Chan, The Vise, White Hunter, Alive on Saturday, Fabian of the Yard, A Prize of Gold, John Wesley, Solution by Phone, The Teckman Biography, Hell Below Zero, Three's Company, Douglas Fairbanks, Jr., Presents, The Broken Horseshoe, BBC Sunday-Night Theatre, The Trial of Andy Fothergill, Captain Horatio Hornblower R.N., Soho Conspiracy, Seven Days to Noon, Hangman's Wharf, The Tragedy of King Richard II, Love in Waiting, Three Blind Mice, The Queen's Husband

Paul Whitsun-Jones was a Welsh actor.

He appeared in the 1966 Dcotor Who story, The Smugglers and the 1972 story The Mutants.

He was educated at Merchant Taylors' School, Northwood, Middlesex. Whitsun-Jones played the role of Mr Bumble in the original West End production of the musical Oliver!