This Doctor Who story was first broadcast in four episodes in 1966.
This audio version consists of a digitally remastered soundtrack with linking narration provided by Peter Purves.
The story was written by Paul Erickson and Lesley Scott. Erickson went on to novelise the serial for Target.
Almost ten million years in the future, the TARDIS materialises on a vast spacecraft including its own miniature zoo and arboretum. The Doctor and Steven Taylor are still explaining the basics of their time travel ability to new companion Dodo Chaplet. It is only a matter of time before they are found and taken to the control chamber of the vessel. Their captors are the mute Monoids, seemingly identical alien beings with a single eye. The Monoids live in peace alongside the humans who command the spaceship, their own planet having been destroyed, but often do much of the menial work. The humans in charge of the ship explain that the Earth is about to be destroyed because of the expansion of the sun, and that this ship is an Ark sent into space with the last remnants of humanity, civilization and various forms of flora and fauna.
The Ark can be downloaded here: