• Season 12, Story 3
• 2 episodes (run times and UK airdates shown below)
  1. (24:29) - Saturday 22 February 1975
  2. (25:04) - Saturday 1 March 1975
• Authors - Bob Baker & Dave Martin
• Producer - Philip Hinchcliffe
• Director - Rodney Bennett

  MAIN CAST

• Tom Baker (The Doctor)
• Elisabeth Sladen (Sarah Jane Smith)
• Ian Marter (Harry Sullivan)

Picture & sound quality: 100%

• Built For War (39:50)
  A documentary about the Sontarans from their first appearance to their most recent in the original TV series. Includes interviews with Terrance Dicks, Elisabeth Sladen, Anthony Read, Colin Baker, Nicola Bryant, Eric Saward, Bob Baker and Stuart Fell.
• Photo Gallery (4:41)
  Selection of stills from The Sontaran Experiment also includes sketch work and behind the scenes stills
• Commentary - Elisabeth Sladen, Philip Hinchcliffe & Bob Baker
  The option to turn on or off audio commentary during video playback.
• Information Text
  The option to turn on or off story information displayed during video playback.

Using the Transmat on Nerva Station the Doctor, Sarah and Harry arrive on a desolate Earth. Although the soon to awaken humans on Nerva may think Earth has been forgotten, the time travellers find that some humans are already on the planet. These humans have been lured to Earth, becoming victims of a lone Sontaran warrior who is conducting experiments on them to determine their value to the Sontaran empire.

Can the Doctor and his friends escape the Sontaran Experiment and make Earth safe for humans once again?