Screenplay by Art Wallace, Johnny Byrne
Directed by Charles Crichton
Edited by Derek Hyde Chambers
"You face power beyond your understanding. It will destroy you."
An Eagle returns from a reconnaissance flight to the planet Terra Nova with the pilots catatonic and an extra man on board. Helena identifies him as her husband, Lee Russell, the pilot of Astro 7 lost in the vicinity of Jupiter in 1994. However, examination of Russell shows peculiarities in his life signs and Professor Bergman determines that he is gradually turning into anti-matter! In obvious distress, Russell warns the Alphans to stay away from the planet, but is unable to explain why. Inexplicably, the man dies and his body disappears. Disregarding Russell's warnings, Koenig and Helena lead a landing party to Terra Nova where they find a paradise environment, perfect for the Alphans. But disaster strikes when the planet apparently turns against them...
Filming Schedule: Monday, January 14th - Wednesday, January 30th, 1974
Original UK Airdate: Thursday, November 27th, 1975 (ATV Midlands)
Original Title: "The Siren Planet"