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Episode Guide
The Ark in Space
Production Code: 4C
Season 12, Story Number 76
Directed by Rodney Bennett

Each episode is identified with date of transmission, duration, ratings in millions, and (for 1963-1974 only) archive status.

Part One
25 January 1975 | 24'58" | 9.4
Part Two
01 February 1975 | 24'49" | 13.6
Part Three
08 February 1975 | 24'05" | 11.2
Part Four
15 February 1975 | 24'37" | 10.2
Archive Status: All four episodes exist in color as PAL 2" videotape, as held by the Film & Videotape Library when audited in 1978.
Tom Baker (Doctor Who), Elisabeth Sladen (Sarah Jane Smith), Ian Marter (Harry Sullivan), Wendy Williams (Vira), Kenton Moore (Noah), Christopher Masters (Libri), Gladys Spencer (Voice), Peter Tuddenham (Voice), Richardson Morgan (Rogin), John Gregg (Lycett), Stuart Fell (Wirrn Operator), Nick Hobbs (Wirrn Operator)
The TARDIS's first port of call is a seemingly deserted space-wheel orbiting Earth in the far future around the 131st century. On board, the Doctor, Sarah and Harry discover that the wheel is an Ark containing the last surviving remnants of the Human race in suspended animation. The Earth was evacuated thousands of years before as solar flare activity threatened to destroy all life, and the cream of humanity was selected to board Space Station Nerva, now renamed the Ark.

The Doctor arrives soon after a visit by a single Wirrn Queen. The Wirrn are an insect species first encountered by humankind on Andromeda. They lay their eggs close to a food source so that their larvae have available nourishment, both physical and mental. The Wirrn larvae also secrete a slime which can physically invade and transform other creatures into Wirrn, retaining the knowledge and intelligence of the host.

On the Ark, the Wirrn Queen had already taken the body of Technician Dune, and with his knowledge of the ship, had laid her eggs close to the solar stacks - the Ark's power source - intending to use the remaining sleeping humans as food stock for her young. This task completed, the Queen had hidden herself away in a storage locker and died.

The Doctor reactivates the controls of the Ark, and accidentally revives a small complement of the crew. The leader, Lasar (nicknamed Noah), becomes infected by a Wirrn grub when he checks the solar stacks and is slowly taken over. Vira, Libri, Lycett and Rogin, however, gradually grow to trust the Doctor and help in his plan to lure the hatched Wirrn insects into a transport ship before ejecting it into space.

With one final act of human sacrifice the Noah/Wirrn neglects to set the rocket stabilisers, resulting in the shuttle exploding in space and destroying the invading Wirrn.

The Doctor offers to pop down to Earth using the Ark's transmat system to ensure that the diode receptor beacons are correctly tuned. Sarah and Harry elect to accompany him and the three leave.

Synopsis from Doctor Who: The Fourth Doctor Handbook by David J. Howe, Mark Stammers and Stephen James Walker, reprinted with permission; further reproduction is not permitted.

Production Team
Russ Karel (Assistant Floor Manager), Barbara Kidd (Costumes), Roger Murray-Leach (Designer), Dudley Simpson (Incidental Music), Sylvia James (Make-Up), Philip Hinchcliffe (Producer), Marion McDougall (Production Assistant), George Gallacio (Production Unit Manager), Robert Holmes (Script Editor), Dick Mills (Special Sounds), Nigel Wright (Studio Lighting), John Lloyd (Studio Sound), Delia Derbyshire (Theme Arrangement), Ron Grainer (Title Music), John Friedlander (Visual Effects), Tony Oxley (Visual Effects)
Story Notes
The Ark in Space set the tone for the early Tom Baker years after the flippancy of Baker's opening story, and is considered a classic by all means. This and the subsequent story were replacements for a six-parter called "Space Station" by Trevor Langley that was canceled. John Lucarotti originally penned the story idea, but Robert Holmes took over the writing when Lucarotti's writing style was considered to be too distant from the current trend and he had no time for a rewrite; Holmes wrote the piece in 18 days. This and "Sontaran Experiment" were sent to production together; although "Ark" was made second, it was aired first. The first episode is the first time since the opening chapter of the two-part "The Edge of Destruction" that the regulars are the only cast members. The Wirrn grubs were constructed by designer John Friedlander out of plastic bubble-wrap packaging, painted with latex and sprayed green. This is the first story to feature the Doctor's yo-yo, which he uses to take a gravity reading. Sets from this story were reused in Revenge of the Cybermen as a cost-cutting exercise (and was incorporated into the script, as it takes place in the same location, yet at another time). The music played to Sarah in part one is Handel's Largo. This was the final time Barry Letts produced the series until he returned in an executive producer role for the eighteenth season (though he directed "The Android Invasion"); ironically, it was one of the most highly-rated serials on the show ever.
For more in-depth information about the contents of this story, a complete episode-by-episode detailed breakdown can be found at the Doctor Who Reference Guide.
Additional, more detailed information about the production of this story can be found at Shannon Patrick Sullivan's A Brief History of Time (Travel).
DVD release
Released in the UK [April 2002] and Australia/New Zealand [May 2002] (BBC DVD catalog #1097), US/Canada [August 2002] (WHV catalog #E1162); episodic format; photomontage cover (UK version by Clayton Hickman). Includes commentary by Tom Baker, Elisabeth Sladen and Philip Hinchcliffe; cast biographies (NTSC only); unused title sequence; original BBC1 trailer for Episode 1; 16mm special effects footage; 1974 6-minute interview with Tom Baker; early 10-minute interview with Roger Murray-Leach; photo gallery; TARDIS-Cam footage from BBCi; an additional track of CGI effects that can be incorporated into the story or watched separately; schematics for the Ark (created in tandem with the new CGI effects). US/Canada version also includes Who's Who and Howard DaSilva introductions (taped for US broadcasts in the late 1970's). Easter eggs: two Tom Baker adverts for the Doctor Who Exhibition and a pre-credit countdown to episode 2.
Video release
Released as �The Ark in Space� in the UK [June 1989] and Australia/New Zealand [January 1989] (BBC catalog #4244), US/Canada (WHV catalog #E1162); omnibus (movie) format, photomontage cover. Rereleased in the UK [February 1994] (BBC catalog #5218), episodic format. Also released on laserdisc in the UK by Encore Entertainment in 1990 (#EE1158).
Audio release
A music suite from the story was released on "Doctor Who: Pyramids of Mars" arranged by Dudley Simpson & Heathcliff Blair, released by Silva Screen (1993); a shorter selection of this music was also released on "The Worlds of Doctor Who" released by Silva Screen (1994).
In Print
Novelised as �Doctor Who and the Ark in Space� by Ian Marter (Target #4), first released in 1977 with cover art by Chris Achilleos. Re-released in 1991 as �Doctor Who - The Ark in Space� with cover by Alister Pearson.
For more details on the various novelizations of this story, with additional background material, artwork and details of both UK and foreign releases, visit On Target.
Screencap Descriptions
Descriptions of each story screen capture above right, top to bottom:
  • The Nerva space station orbiting Earth
  • a dead Wirrn
  • the Doctor (Tom Baker)
  • Noah (Kenton Moore) is almost completely turned into a Wirrn
  • Harry (Ian Marter) tends to Sarah Jane (Elisabeth Sladen)
  • Vira (Wendy Williams) and Rogin (Richardson Morgan) on the transport ship
  • Sarah in the processing room
  • a screen capture from the DVD release with new special effects, demonstrating the Nerva beacon rendered in CGI (see DVD section)