Sick but gripping....(Caution: Spoilers!)
Definitely a 'tale of two psychopaths.'
They all played their parts well.
What I didn't like was when the one psycho was talking to the camera and also when he rewound the scene they were all in. It took rather than gave to the movie. Kinda stupid, IMHO.
Regardless, good movie, but obviously not for everyone. Grade: B.