Goodbye Gemini (1970) - Producer Peter Snell (aka Twinsanity) is a 1970 thriller directed by Alan Gibson from the novel Ask Agamemnon by Jenni Hall. Two 20 year old twins have a bizarre incestuous relationship. Julian (Martin Potter) and his sister Jacki (Judy Geeson) carry on the affair and only reveal their secrets to a stuffed teddy bear named Agamemnon. While their father is absent, they murder the housekeeper and run wild at night. Drop out parties with transvestites, drugs and homosexuals leads to blackmail, debauchery and murder. Julian soon finds himself unable to escape the dark and strange world and finds his fantasies have become his worst nightmares. Michael Redgrave appears briefly as a member of Parliament. Stars Judy Geeson, Martin Potter, Michael Redgrave, Alexis Kanner, Mike Pratt. Director Alan Gibson.

Goodbye Gemini (1970)   http://www.imdb.com/title/tt0065790/