Whatever moral issues exist in this strange tale of the occult, they vanish as soon as you accept the premise of this story--that a woman would kill another to repossess her husband with both of them in the guise of someone else's body!! It's about as weird as any Tales from the Crypt!
On the plus side, all of it is stylishly photographed and played with a certain amount of relish, at least by Jacqueline Bisset, Curt Jurgens and Bradford Dillman. Biggest flaw is casting Alan Alda in the central role as the pianist who inherits the musical talent of Curt Jurgens when the Satanist dies, bequeathing Alda with his body and soul. Bisset is the wife who slowly comes to suspect that her husband has been taken over by someone else.
Not quite as strikingly original as "Rosemary's Baby", it does have some effective horror moments, notably involving scenes with a rather ferocious black dog and a scene where the Devil is summoned but we never actually see him. Imagination is given free reign here (at least fleetingly), shades of Val Lewton. Perhaps a technique that should have been used more often throughout.
None of it quite makes sense and the ending is a distinct letdown, but there are some chilling moments nevertheless. Bisset and Parkins are beautifully photographed, with Bisset coming out ahead in the acting department, playing the stressed out wife with appropriate fear and tension. Parkins, on the other hand, seems to rely on one frozen expression, sleepwalking through her role, relying solely on her looks to get by in a way that Hedy Lamarr was often accused of doing in films of the '40s.
As for Alan Alda, he is much too bland, lending neither interest nor credibility to a role that demands a strong romantic lead. His career suggests that he is clearly more comfortable in character roles requiring comic flair, not straight dramatic parts. Bradford Dillman is at least a stronger presence in a lesser role.
All in all, not bad for watching when you're in the mood for a tale of the occult. I seem to recall enjoying the book years ago and the film doesn't quite measure up. It emerges as one of those films that could have been much more satisfying with better casting and direction.
