An surveillance specialist falls prey to his own paranoia and guilt.
The most fascinating aspect of this very suspenseful film was definitively the pacing. It builds up extremely slow and the climax in the hotel room is just as masterful as it is simple in the direction. Definitively a must-see with the directors commentaries.
Also, Gene Hackmans portrayal of Harry Caul was extremely convincing - a very troubled hero and all his actions are very much motivated by his backstory, which only gets revealed gradually. There are some issues in the dream scene, which was too much back story and rather strange from the cinematography.