The TARDIS is suspended in space and the Doctor, Ian, Barbara and Susan are confused and frightened by a series of mysterious events.

On the Moon, the Doctor is captured by the Ice Warriors as he spacewalks to the T-Mat relay station. He learns that they intend to use T-Mat to spread a deadly fungus across the world.

The Doctor subjects himself to a dangerous experiment so that he can access the memories of the dead Wirrn Queen. Elsewhere, the larvae Wirrn are pupating into their adult form.

Terry Wogan hosts a new comedy quiz game in which contestants attempt to match their 'blanks with six guest celebrities. A game all the family can play at home; a game with no right or wrong answers - a simple formula which relies on everyone to be witty with words.

Played Guy Fawkes on the online game The Gunpowder Plot

Sharon Duncan-Brewster is a British actress. 

She is perhaps best known for her role as Crystal Gordon on the Bad Girls during the first four series, her role as Trina Johnson on EastEnders and her role as Maggie Cain in the autumn 2009 Doctor Who special, The Waters of Mars.

She portrayed the role of Crystal Gordon in the first four series of ITV prison drama series Bad Girls. After leaving the programme at the end of its fourth series she guest-starred in Holby City, Waking the Dead, Babyfather and daytimesoap opera Doctors. From February to September 2009 she appeared on the BBC soap opera EastEnders as Trina Johnson, estranged wife of Lucas Johnson. The character was killed off during a row with Lucas, who pushed her, impaling her throat on a rake.  

Sharon also appeared on the medical TV series "Body Story" in 1998. In the episode, Sharon played a club singer and influenza patient named Holly Jones. The episode documented the radical transformations her character's body went through in order to stop the influenza virus. In 2011, she appeared in all four episodes of TV drama Top Boy.

Trinny Woodall is an English fashion advisor and designer, television presenter and author. She was raised in a wealthy family and was privately educated. After ten years working in marketing – and battling alcoholism – Woodall met Susannah Constantine in 1994, whom she joined to write a weekly fashion column for The Daily Telegraph. This led to the launch of their own internet fashion-advice business and the release of their first fashion-advice book, both of which ventures ended in failure.

They were then commissioned by the BBC to host What Not to Wear in 2001. The following year Woodall and Constantine released their second book, What Not to Wear, which gained them a British Book Award and sold over 670,000 copies. The pair co-wrote many fashion advice books, several of which became best-sellers in the United Kingdom and the United States, and have now sold over 2.5 million copies worldwide. In 2009 she Launched their International Makeover Mission series. They have filmed over 20 series in 9 countries including, Norway, Sweden, Israel, Denmark, Australia, India, Netherlands.

In 2003 they launched their shareware range Trinny & Susannah's Original Magic Knickers which are sold in 30 countries around the world

After co-hosting What Not to Wear for five series and appearing on The Oprah Winfrey Show as style and make-over advisors, Woodall and Constantine moved to ITV to host Trinny & Susannah Undress... in 2006, and Undress the Nation. After becoming the faces of Littlewoods Direct, they released their own Littlewoods clothing range and latest fashion advice book, The Body Shape Bible, in 2007.

Malorie Blackman is a British writer who held the position of Children's Laureate from 2013 to 2015.

She primarily writes literature and television drama for children and young adults.

Blackman's first book was Not So Stupid, a collection of horror and science fiction stories for young adults, published in November 1990.

She has since written more than 60 children's books, including novels and short story collections, and also television scripts and a stage play.

Her work has won over 15 awards.

Blackman's television scripts include episodes of the long-running children's drama Byker Grove as well as television adaptations of her novels Whizziwig and Pig-Heart Boy.

Roger Lloyd Pack was an English actor known for his roles in the TV shows The Vicar of Dibley, Only Fools and Horses and The Old Guys, as well as his role in the film Harry Potter and the Goblet of Fire.

He played John Lumic, the owner of Cybus Industries and the creator of the Cybermen, in the 2006 Doctor Who story Rise of the Cybermen/The Age of Steel. 

The actor was born in Islington, north London in 1944, the son of Hammer horror actor Charles Lloyd-Pack. He studied at the Royal Academy of Dramatic Art before making his stage debut in Northampton. He had small appearances in The Avengers and Virgin of the Secret Service before his big screen debut in 1968 when he played a small part in The Magus. Other TV roles included parts in Spyder's Web, Crown Court, Dixon of Dock Green and Terry Nation's Survivors where he played Wally. He appeared in Life of Shakespeare, Private Schulz, Moving, Byker Grove, Selling Hitler, The Bill and The Gravy Train Goes East. In later years he had roles in The Borgias, Tinker Tailor Soldier Spy and The Old Guys. 

He was a committed socialist, he campaigned for nuclear disarmament and was a supporter of Left Unity.

For his professional name, Lloyd-Pack did not use the hyphen in his surname.

He died in 2014 after a battle against pancreatic cancer.

Reginald Jessup appeared in two Doctor Who stories: as the Servant in the 1966 story The Massacre of St Bartholomew's Eve and Savar in the 1978 story The Invasion of Time.

Also appeared in The Bill, Shine on Harvey Moon, The Tragedy of Coriolanus, Play for Today, Escape, Hamlet, Prince of Denmark, Julius Caesar, Rebecca, In the Forest, Target, 1990, The Signalman, Softly Softly: Task Force, Z Cars, The Befrienders, Dixon of Dock Green, Hardy Heating Company Ltd, Department S, Softly Softly, The Champions, The Avengers, Gideon's Way, The Baron, The Spies, Theatre 625, Reluctant Bandit, The Wednesday Play, The Saint, Curtain of Fear, Maigret, The Sword in the Web, BBC Sunday-Night Play, Silent Evidence, Sir Francis Drake, Boyd Q.C., Drama 61-67, Danger Man, Fact and Fiction, No Wreath for the General, Here Lies Miss Sabry, Armchair Mystery Theatre, Blood Wedding, This Desirable Residence, ITV Play of the Week, Hour of Mystery, Vanity Fair, The Count of Monte Cristo, Quatermass II, Puck of Pook's Hill

Jane Lumb was an English fashion model and actress in the 1960s.

Lumb was well known for appearing in series of advertisements for Fry's Turkish Delight.

She found fame in the very first international edition of the Pirelli calendar in 1964 when she posed on a beach in Spain.

She had small parts in a number of films including A Hard Day's Night and Goldfinger. 

Elroy Josephs played Jamaica in the Doctor Who serial The Smugglers.

Also appeared in Brideshead Revisited, A Private Enterprise, Stage 2, Love Thy Neighbour, Theatre 625, Quatermass and the Pit, Adam Adamant Lives!, The Wednesday Play , Dixon of Dock Green, BBC Sunday-Night Theatre, ITV Play of the Week

Cyril Luckham was a British film, television and theatre actor.

Luckham played the White Guardian in Doctor Who. He appeared in The Ribos Operation, the first serial in The Key to Time season, and Enlightenment. 

He appeared in an episode of Randall and Hopkirk (Deceased) (1969), as the villain.He appeared the 1978 TV series based on The Famous Five books by Enid Blyton, as the evil psychic Edward Drexel in the 1979 supernatural thriller series The Omega Factor, and as the equitable Chair of the school board of Bamfylde in the 1980 Andrew Davies adaptation of To Serve Them All My Days. He also portrayed Archbishop Thomas Cranmer in the film adaptation of A Man for All Seasons (1966) and the long-suffering Father O'Hara in Some Mothers Do 'Ave 'Em.