It's amazing to think that dozens - maybe hundreds(?) - of movies, especially from the Lifetime channel, can trace their lineage to this film (and people like John Carpenter and Brian De Palma turned this down in part as they saw it as unoriginal, taking from Clint Eastwood's great debut, Play Misty for Me). I think that makes this hold up is the acting, pure and simple. Douglas and Close and also Anne Archer as the wife really make this material work as strong as it can - they sell every minute they can, and they have to. This is even in knowing that the movie doesn't really have a very firm moral leg to stand on; we should be on Michael Douglas' side, but he's the one that screwed up.
Sure, Glenn Close is crazy, or a victim of abuse as well if one wants to dig a little deeper (who knows what happened with dear old dad before he died of that heart attack), but, and this is important, she's right (certainly initially) or at least has a point that should matter about how he's just tossing her to the wayside after a night or two of "fun". I like that Lyne and the writer have underlying implications that make it more harrowing and that it paints the two sides as neither right or wrong (though of course one is more wrong than the other, the wrongs don't make anything right) up to varying degrees. What makes it not stand up over time is the ending, or even the last act.
From a writing perspective it should have ended how it was originally supposed to, with Alex killing herself and framing Dan as if it was murder. It calls back to the mention of Madame Butterfly, which is the set up and pay-off. But because the producers acquiesced it turns into the template for countless s***y movies where the character has one last hurrah to mess with the supposed heroes and blood is spilled and one more life is lost. In a sense my criticism is the same as Ebert's, that it kind of turns into a Friday the 13th movie. But at least for 85% of the running time, maybe 90%, it is a provocative, terrifying drama that has a simple moral message: don't cheat.
