This Week in USA
Colony In Space: Episode Four (HHH4)
Last updated 12 April 2026
7:30pm-8:00pm EDT (23:30 GMT) < «
Retro TV
Featuring: Jon Pertwee, Katy Manning, Tony Caunter, Roger Delgado, Bernard Kay, Morris Perry, John Ringham, Helen Worth
The Doctor discovers a doomsday machine left by a highly advanced civilization.
Synopsis Source: TVPassport listings
Broadcast Source: Retro TV