An alien vessel manages to break the earth defense systems. Captain Layton is sent to investigate and find the invaders. Together with friends from the planet Ganymed he discovers the enemies in a hidden underground city on earth.
as Captain Mike Layton
as Diane Greene
as Irk
as Colonel Dawson
as Dr. Helen Parker
as Frank Bimble
as Lt. Vassilov
as Captain Connolly
as Professor Burton
as Replicant
as Herman Wesson
