“The Square Triangle” is episode ten of season one of UFO.
A woman is driving a car down the road when a man’s hand reaches from the back and holds her leg.
MoonBase has spotted a potential UFO and S.I.D. confirms it. Interceptors are launched. Straker is told the course terminate in southern England. He looks at maps of the area, and tells Foster he will give the command to fire. Then states they won’t intercept.
The UFO lands and the area is cordoned off. Mobiles are dispatched and Straker tells Foster to accompany them.
The man is now in the front of the car and it’s in the same area the UFO has landed in. The woman tells him not much further. They arrive at a house and he compares the interior to some photos. He tells the woman, Liz, she did a good job. And to go get it. It is a gun.
Mobiles are on sight and Freeman speaks to Straker at SHADO Control about letting one through. Straker heads to his office and says they are fighting a series of losing battles because they don’t know what they’re fighting. He’s been waiting months for this kind of opportunity; a UFO on their own doorstep. He wants the mobiles to bring it in intact before any deterioration sets in. Straker agrees there’s a risk, but the area is low population.
The mobiles are searching for the UFO but a game warden and his dog have found it. The man gets attacked by an alien, and gets his dog to attack the alien as he runs off. The alien eventually drives the dog away. The warden has run back to the UFO and gets shot; the alien drags the body away then destroys the UFO.
SHADO are looking for the UFO whilst the woman and her lover are plotting to murder her husband that night. As there’s an alien wandering around in the same area.