I just bought this movie today, and I have to say, I'm glad I did it.
A young boy is brought in for heart surgery, and experiences Anesthesia Awareness. No one believes him when he tells them he felt everything, and the horrible trauma is enough to turn him psychotic. 20 years later, he's now grown up, incognito, and out for vengeance against the same doctors...and their families.
This is an amazingly rich film...although it has some very unpleasant imagery that's not for the weak of heart (most notably the surgery scene at the beginning).
If you can get past that however, you'll be treated to a deep murder mystery that's engaging, emotional, and pulls no punches. The acting is superb, and the director does a fine job of keeping up the tension level throughout.
I should point out that this DVD is subtitled, with no English dub, which may turn some people off. But, if you don't mind that, and you've been looking for another good foreign film to add to your collection, I strongly suggest hunting this title down.
(FYI: This film is also known under the title "Return" )