It's all here. Hitchcockian style, haunting music and intrigue. Usually ingredients I really love in a thriller. I don't mind suspending disbelief if it provides a real enjoyable surprise that you can't see coming. But if it is one that is so far fetched and illogical then I have to drawn a line of what I deem acceptable. The tale that is being told is without a doubt very twisted for sure. Only how it unfolds is quite messy. The acting overall is rather poor. Only John Lithgow brings it to a whole new level. Maybe it is me, but to me it looked like that Brian De Palma's heart was not in this one. Or that he had something else in mind but had to leave out certain elements to avoid upsetting the big studio bosses. With the consequence that Obsession doesn't pay off as most of his films do. Whatever the motivation or reason behind it the viewing experience will be one of confusion and frustration.
I don't think this is a total waste of time. It's good to see that even a master can make mistakes. Undoubtedly some people will disagree and say that Obsession is underrated and that there is much depth to it. If you delve into the psychology of the characters then of course you will be able to rationalize a lot of the acts and events occurring in the film. However even then you can't deny that most of them are far too illogical to accept. And again I would have taken that for granted if the end result was satisfying. But it's not. Do give this a shot and preferably watch this with fans of the genre. You will have some nice and probably heated discussions. However do expect to be disappointed a little because we have seen De Palma do much better.