The Last Enemy (S01E24)

Moonbase Alpha finds itself caught up in war between two planets - and the wiles of a beautiful women. Two planets come into view, and then an approaching spaceship. On Moonbase Alpha, Commander Koenig orders a Red Alert. Defensive Eagles are instructed to be ready for take-off, but not one is able to move. One by one, their engines fade and die and at the same time Alpha's power fails. (iTunes)