One of the bizarrest examples of films based on a true story, Jeremy Irons plays twin gynaecologists Beverley and Elliot Mantle. They share every experience; as Elliot says "Bev, you haven't done anything until I've done it too". But when Beverley falls in love with one of their shared women, Claire Niveau (Genevieve Bujold), but does not dutifully report the experience to his brother, he spirals into madness...
The 'gimmick' of having one actor play both roles rather than casting twins is not entirely about box office appeal. Because Beverley and Elliot are literally the same person, their identities merge and it's hard to tell them apart. Irons has the perfect balance in making them different enough to initially distinguish between them (Beverley is shy and nervy whereas Elliot is suave and the alpha of the two) but also having times where it's tricky to mentally separate them. They're also both childlike, giving the sense that they feel permenantly connected by the literal connection they had in the womb. By refusing to share his personal experiences, Beverley realises that this connection is unhealthy yet he cannot break it without destroying his brother. However even the acknowledgement that their bond is unnatural puts Elliot at risk. They are genuinely one body operating as two.
The film is particularly disturbing for women, as Beverley becomes obsessed with the idea of 'mutant women' and devises torturous gynaecological instruments to deal with them. Some may be put off by the misogyny but Elliot and Beverley's mistrust of women is clearly signalled from when they were children. There's some very creepy uses of the colour red in this film; let's just say that Elliot and Beverley are not the type of gynaecologists you'd want to see.
The camera trickery needed to make us believe that Jeremy Irons is communicating with another self is effective. Mostly that's down to Irons' brilliant performance and his great chemistry with, er, himself. Add in some twincestuous undertones and the practical tricks such as optical illusions, doubles and some artful shooting are pushed to the back of your mind by the brilliant psychological mindscrew.
The weak link is Bujold, who is quite bland as Claire. There is a moving scene when she realises she will never be able to have children but she is more of a symbol and catalyst for Beverley to rebel rather than a character. Claire is treated horribly in a way that would certainly put you off dating twins, yet it never occurs to her to break off the relationship or to mess with their heads. Obviously watching Jeremy Irons talking to himself is the real appeal but your mileage may vary as to how much misery you can watch women suffer.
This kind of biological horror, with the body and its functions as the monster, is typical Cronenberg so if you like David Cronenberg's films, this is a brilliantly chilling exploration of that. The fetishistic possibilities are not as overt as in Crash but they are certainly there. Whilst it's an uncomfortable watch (particularly for twins!), it is very compelling as a study of the symbiotic relationship between twins with their gynaecological studies as a revenge for the biological bond that dooms them.