She lived two amazing lives under his spell!

Murray stars as Dr. Bill Leggat who, along with his childhood friends Lena and Robin, creates a machine that can flawlessly replicate anything, be it animate or inanimate. Undermining the trio's professional relationship is the sexual tension that has been brewing for years. Both men are attracted to Lena, but, on the eve of the public announcement of their invention, Lena declares her love for Robin. Devastated, Bill decides to clone Lena, and names the clone, who has all of Lena's feelings and memories, Helen. Confident that Helen will love him, Bill takes her on a holiday. However, while away, Bill's relationship with Helen does not go as planned, causing Bill to resort to some shady experiments on Helen that will force her to love him.

Produced by Hammer studios and directed by their most celebrated director, Terence Fisher, Four Sided Triangle was something of a precursor to many of their most famous films.