A call for help reaches Moonbase Alpha from the survivors of a dying world. The world is one that has been flying through space for 900 years with contrasting inhabitants. Some have never changed while others have reverted to barbarism. Does this new planet represent hope to the Alphans or something potentially dangerous?
Elenco: Martin Landau , Barbara Bain , Catherine Schell , Barry Morse , Tony Anholt , Nick Tate , Prentis Hancock , Zienia Merton , Clifton Jones , Anton Phillips .