The crew of the USS Enterprise deals with an indestructible planet-destroying space probe.
Quest roles:
Frank da Vinci(Lt. Clifford Brent), Eddie Paskey(Lieutenant Leslie (uncredited)), Vic Perrin(Tharn), Makee K. Blaisdell(Singh), Roger Holloway(Lt. Lemli (uncredited)), Marc Daniels, Barbara Gates(Crewman)