Hollywood starlet Barbara Payton stars in this gripping sci-fi thriller, two brilliant scientists unlock the secret to duplicating life, only to find their actions have deadly consequences. When they use their invention to clone the woman they both love, a dangerous love triangle ensues. With mind-bending twists and a chilling exploration of human nature, Four Sided Triangle blends classic British sci-fi with psychological suspense, proving that some inventions are best left unexplored.  

Never before seen on Blu-Ray in the UK, Four Sided Triangle makes its debut as a brand-new Hammer 4K restoration from the original negative film elements. Co-written and directed by Hammer legend Terence Fisher.

• New commentary with film and media historian Melanie Williams and film researcher and critic Thirza Wakefield.
• New commentary with actor and film historian Jonathan Rigby, author of English Gothic, and Kevin Lyons, editor of the Encyclopaedia of Fantastic Film and Television website.
• I Am Not Ashamed: Film historian Lucy Bolton takes an unvarnished look at Barbara Payton, her body of work and her riches-to-rags story of Hollywood excess in an unenlightened and censorious age.
• In the Sticks Sci-Fi!: William Fowler and Vic Pratt, creators/curators of the bfi’s ongoing Flipside series, discuss and deconstruct this key example of Hammer’s science-horror output.
• Things to Come: Film historian and writer Neil Sinyard examines Four Sided Triangle, its stars, direction and problematic sexual politics.
• An extensive image gallery, including behind-the-scenes images, alongside tracks from Malcolm Arnold’s score.