Francis Ford Coppola film (between The Godfather Parts I and II). Gene Hackman plays Harry Caul, a surveillance expert who works for private clients. He records a conversation in a busy public quad in San Fransicso between a man and a woman, triangulating with three different receivers and piecing the tapes together with sophisticated (for 1974) reel-to-reel audio equipment. He does not know what the conversation means, but his client, The Director (Robert Duvall) and his assistant (Harrison Ford) won't tell him. He fears, however, for the lives of the man and the woman and feels guilty for what he has done, not knowing the consequences.
Caul is a lonely man. His apartment is bare - stripped of personal possessions. He doesn't like people to know that he has a phone in case it gets tapped. His door has three locks and an alarm. He sits alone at night playing his saxophone to a backing record. He has an odd, secret relationship with a woman who seems to be stowed away in a basement apartment all day waiting for him. When she starts asking too many questions, he breaks it off. Gradually, he becomes more and more paranoid and suffers from nightmares and visions about the couple he has spied on.
The audio from that conversation is repeated throughout the film, slowly acquiring its meaning and significance. The soundtrack is crucial to the film's atmosphere - particularly that alien distortion when the mics aren't picking up the conversation properly.
Nugget: at 113 minutes this is perhaps a little too long. Uncomfortable viewing at times during Hackman's panics. Featuring the Worst Jacket in Movie History: Hackman's shapeless grey raincoat that sticks up at the back.