“You’re not very brave, are you?”

Goodbye Gemini (otherwise known by the far more entertaining title Twinsanity) sees a coming together of two different styles of exploitation. On the one hand, you have a couple of innocents abroad in swinging London (like in Pete Walker's sexploiter Cool It Carol), and on the other, the pair's childishly murderous antics bear more than a slight resemblance to those in the bizarre Mumsy Nanny, Sonny And Girly.

The twins of the alternative title are Julian and Jackie (Martin Potter and Judy Geeson), who arrive at a London house and waste no time in killing the woman who lives there (by placing their teddy bear, Agamemnon, at the top of the stairs for her to fall over).

Out on the town, they meet a swinging couple, Clive and Denise. Clive (and his astonishing sideburns) appears to have designs on Jackie despite already having a girlfriend, but what he doesn't know is that Julian is having similar thoughts about his sister (urgh).

The pair are taken to a swinging party (there's a lot of swinging goes on in this film) on a houseboat by Clive, where an old fruit called Garfield asks him: "Your friends are sweet, Clive… which are you interested in?"

When told that someone's after him, the extremely shifty Clive takes the twins away - and not a moment too soon, as gangster Rod (an extremely swinging Mike Pratt) arrives with murderous intentions for Clive.

Clive and Jackie pair up, leaving an unhappy Julian with Denise.

Clive "You're like a little clockwork toy, aren't you?"

Jackie: "With a little piece missing…"

But the next day (and perhaps because Jackie's proving a little hard to get), it's Julian who the libidinous Clive targets, spiriting the young lad away for a spot of mild drug abuse and some "party time" in a seedy boarding house. "Party time" consists of a woozy Julian being set upon and burgled by a couple of transvestites, turning up at home the next morning slightly the worse for wear and a bit bandy-legged.

"You're very bright and eloquent this morning, did you spend the night in a Turkish bath?" asks Jackie.

"Sort of," he replies (he's calmed down a bit since entering the house, when his first words to her were "I feel… awful" and "I can't tell you!").

Whilst Julian was widening his "horizons", Jackie and Denise were visited by Rod the gangster, who returns the next day and beats the crap out of Clive (hooray!) in front of an unimpressed Jackie.

"You're not very brave, are you?" she tells the bleeding fop after Rod has left.

Clive plans to blackmail Julian with photos taken during his tryst the other night, but is foiled by Denise, who spills the beans to Jackie.

Things then take a very sinister turn, with the twins deciding tgo take their revenge on Clive in an extremely violent way…

Goodbye Gemini is typical early 70s fare, enlivened by some terrible fashions, a few barking mad ideas and a number of very famous cameos (including, amazingly, Michael Redgrave, and not quite so amazingly, Freddie Jones).