4C. The Ark In Space

Season Twelve - 1974/1975

Script Editor: Robert Holmes
Writer: Robert Holmes
Produced by: Philip Hinchcliffe
Director: Rodney Bennett
Designer: Roger Murray-Leach
Incidental Music: Dudley Simpson


The TARDIS materialises on board a space station. Everything is fully automated, including defence systems, and the station seems to be deserted, until the Doctor and Harry find a room full of humans held in suspended animation - and also the body of a dead Wirrrn.

One of the bodies is missing, and when of the people are revived, the Doctor and Harry are accused. Meanwhile, Sarah laid down on a bench, and was teleported to the cryogenic facility.

Investigations by the Doctor find that the station has been invaded by the Wirrrn. The Wirrrn had damaged the machinery that controlled the de-freeze process, hence the people failed to awaken at the right time.

The Wirrrn had been using the people as food. The humans' leader, Noah, was assimilated by the Wirrrn, giving them access to all his memories. The Doctor used this to convince Noah, who was now a Wirrrn himself, to take the Wirrrn outside the space station. When the shuttlecraft's engines were fired the Wirrrn were destroyed.

The original idea was for the people on board the space station to return to Earth when the solar flares had calmed down. The transporter was not functioning properly, and the Doctor offered to go down to Earth and fix the problem.

Regular Cast

  • Sarah Jane Smith: Elisabeth Sladen
  • Harry Sullivan: Ian Marter

Guest Cast

  • Voices: Gladys Spencer (1,3), Peter Tuddenham (1)
  • Vira: Wendy Williams (2-4)
  • Noah (Lasar): Kenton Moore (2-4)
  • Libri: Christopher Masters (2)
  • Rogin: Richardson Morgan (3-4)
  • Wirrrn Operators: Stuart Fell (3-4), Nick Hobbs (4)
  • Lycett: John Gregg (3)
  • Dune: Brian Jacobs (1,3)
  • Wirrrn Grub: Stuart Fell (2-3)
  • Bodies in Palletts: Richard Archer, Geoff Brighty, Rick Carroll, Sean Conney, Peter Duke, Jan Goram, Brian Jacobs, Tina Roach, Lynn Summer, Barry Summerford

Original broadcast on the BBC

Channel Title Date Viewers Rating
BBC 1 386. Part One Saturday, January 25, 1975 5:35 PM - 6:00 PM 9.4M
BBC 1 387. Part Two Saturday, February 1, 1975 5:30 PM - 5:55 PM 13.6M
BBC 1 388. Part Three Saturday, February 8, 1975 5:30 PM - 5:55 PM 11.2M
BBC 1 389. Part Four Saturday, February 15, 1975 5:30 PM - 5:55 PM 10.2M

Click here to show repeat broadcasts on the BBC


  • Television Centre Studio 1
  • Television Centre Studio 3


Part 1: Watch out for Liz Sladen's knickers. They appear when Harry and the Doctor lift Sarah onto a couch to recover from her fit of suffocation, and as she is lifted her dress flaps down at the back, showing a brief glimpse of her knickers. Liz Sladen later said that she regularly used to receive requests by post for those particular undies.


Part Two of this story achieved the highest ever ratings position for Doctor Who - 5th!