Grim danger emerges from the past as Alpha is threatened with destruction from an unmanned spacecraft. The ship was sent up from Earth many years earlier with tragedy in its wake. If this threat wasn't enough, victims from outer space threaten revenge.
Elenco:
Martin Landau
,
Barbara Bain
,
Catherine Schell
,
Barry Morse
,
Tony Anholt
,
Nick Tate
,
Prentis Hancock
,
Zienia Merton
,
Clifton Jones
,
Anton Phillips
.