The great thing about obscure B movies is that you never know when they're going to be better than the A films they're ripping off. Body Chemistry is an almost scene-for-scene imitation of Fatal Attraction, but it's darker, deeper, and scarier-superior in everything except budget and flash.
A California scientist (Marc Singer) has a happy home life with his wife (Mary Crosby) and son until he gets pulled into a seriously sexy affair with a fellow researcher, played by Lisa Pescia. The lady gets kinky and demanding, Singer tries to bail out, and she starts stalking him. None of this is news. But where Attraction let Michael Douglas off pretty much scot-free in the guilt department, Body Chemistry doesn't budge an inch. Nice-guy Singer carries the affair well past the point of sympathy, and by then it's clear that the kinks he's fleeing are really his own. Pescia's motivations are equally ambiguous, and the film's shocker of an ending makes perfect sense even while it's throwing you for a loop.
Kristine Peterson's direction is stylish yet firm: She wants to make this movie as creepily thought-provoking as possible, and she succeeds. Fatal Attraction was a high-tech roller coaster that was over the second the lights came up. The demons in this much smaller movie linger on. A-