The Earth is about to plunge into the sun.  All the Earth's plant, animal and human life (much of it miniaturized and in suspended animation) is on a huge Ark on a 700 year journey to a new planet,  Refusis.  Dodo has a cold, against which Steven, the Human Guardians of the Ark and the slave race called the Monoids have no immunity.  The Doctor eventually finds a cure, and the travelers take off.  In episodes 3 and 4 the TARDIS lands on the Ark 700 years later - at the end of the voyage to Refusis.  As a result of another bout of the cold, the Monoids are strong and have made the Guardians their slaves.  With the help of the invisible Refusians, the Doctor forces the Monoids and the Guardians to make peace and live together on Refusis. 



The Doctor: William Hartnell
Steven Taylor: Peter Purves
Dorothea "Dodo" Chaplet: Jackie Lane

Guest Appearances:
Commander: Eric Elliott
Zentos: Inigo Jackson
Manyak: Roy Spencer
Mellium: Kate Newman
Rhos: Michael Sheard
Baccu: Ian Frost
Monoids: Edmund Coulter, Frank George
Monoid Two: Ralph Carrigan
Yendom: Terence Bayler
Monoid One: Edmund Coulter
Monoid Three: Frank George
Monoid Four: John Caesar
Monoid Voices: John Halstead, Roy Skelton
Guardians: Stephanie Heesom, Paul Greenhalgh
Maharis: Terence Woodfield
Dassuk: Brian Wright
Venussa: Eileen Helsby
Refusian Voice: Richard Beale

Producer:  John Wiles.
Script Editor: Gerry Davis.
Writer:    Paul Erickson,Leslie Scott ( Credited but had no input to the script).
Director: Michael Imison
Designer: Barry Newbery.
Costume: Daphne Dare.
Make up: Sonia Markham.
Music: Tristram Cary (re-use of music originally composed for "The Daleks"), also stock ("Drumatics No. 11" by Robert Farnon) 

Novelised as "Doctor Who - The Ark" by Paul Erickson (0 426 20253 8) first published by W.H. Allen (now Virgin Publishing Ltd.) in 1986 with cover by David McAllister.  New edition in 1992 with cover by Alister Pearson.  Target library number 114.

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Released as "The Ark" in the UK in October 1998, and in Australia & New Zealand (BBC catalogue #6609); Released in US and Canada, in March 1999, (CBS/FOX catalogue #0157); Released in episodic format, with photomontage cover

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Jackie Lane (Dodo) played the role with alternating accents.
Paul Erickson and his wife Lesley Scott received credit for writing the story, although Leslie Scott did not contribute to the script.
This was the final story that John Wiles produced.

All four episodes exist as 16mm telerecordings. A print of episode three was held by the Film & TV Library when audited in 1978. Negative film prints of all four episodes were recovered by BBC Enterprises circa 1978.

Ealing filming. (31 January - 3 February 1966)
Studio recording in Riverside 1. (18, 25 February; 4, 11 March 1966)

Episode 1 - Throughout the story, the actor playing the Commander appears to be wearing badly-fitting dentures!
Episode 1 - The Doctor notices Dodo's daft costume and asks her: "Have you been fruiting about in my wardrobe?" (or something that sounds very like 'fruiting').
Episode 1, 2 - At the end of episode 1, Zentos says: "Take them to custody and later they will be made to suffer for the crime that they have committed." However, in the episode 2 reprise, this becomes "...they will be made to answer for the crime..."
Episode 2 - As Zentos talks with the others about the verdict, watch out for the guy on the left who doesn't know where to put his hands, as he realises that the costume designer forgot to add pockets!