SPOILERS.

Coppola made this, a personal movie, after the rip-roaring commercial and critical success of "The Godfather." And it's a good one. Whereas "The Godfather" was a splashy violent well-done gangster movie dealing with power and sex, and persuading us to sympathize with a family at least as murderous as that in "The Texas Chainsaw Massacre," this one has to do with something else entirely. It's not about that old theme of illusion vs. reality. Nobody plays, say, Jack the Ripper in a stage play and then begins to butcher women on the streets. It has to do, rather, with the interpretation of reality (whatever that is), which is an issue of a different color.

Briefly, Harry Caul (Hackman) is hired by "the director," who seems to be a rich and powerful executive, to spy on a young woman and the guy she's seeing (Cindy Williams and Frederick Forrest). He's the best surveillance technician on the West Coast and he does an ace job of capturing them on film and audiotape while they wander around Union Square in downtown San Francisco. Harry puts the pieces together and suspects the Director plans to murder them. Well, this isn't Harry's first time at bat here. Back in New York, doing his usual dispassionately expert job of spying, he was responsible for the deaths of a man, his wife, and his child, the incident that drove him to The City. He's a very secretive guy, Harry, and minds his own business, but he's not about to let THAT happen again. When he tried to withhold his tapes from The Director, the tapes are stolen. And when he tries to interfere further a murder does in fact take place. But Harry had it backwards. He interpreted everything on his tapes as signs that the young couple were in danger from The Director, whereas in fact the couple had been planning to murder him for the inheritance, and they succeed too.

You can never truly be sure that your interpretations of what's going on are the correct ones because, as Kant argued, our interpretations are limited by our perceptual apparatus, just as Harry's interpretations were limited to what he could learn from four unidirectional microphones, a camera, and a hidden portable mike attached to a receiver. And what all this electronic junk told him was real enough but so ambiguous that its meaning could be twisted one way or another.

The movie is rife with symbolism that I'm not sure I'm getting because it too is ambiguous. Harry is as secretive as anyone can be without being frankly paranoid. Nobody knows his home phone number. His girlfriend, who deserts him, doesn't know his birthday or his age. A "cawl" is the thin layer of white fat that covers and conceals a piece of meat such as a leg of lamb. But Harry's raincoat is translucent, one of those ugly plastic ones you can pretty much see through. And he wears prominent glasses so his sight can't be what it used to be. And, after all, an envious competitor in the bugging business does manage to plant a hidden mike on Harry and record a private conversation. And somebody does get Harry's home phone, calls him up and tells him, "We're watching you." (This leads to Harry's tearing his whole apartment apart in a futile search for the hidden mike, and leaves him playing a desolate tenor sax while sitting alone on the floor.) Harry has no family. His assistant, John Cazale, is a little too inquisitive and is fired. Someone describes Harry as "anonymous and lonely." But he's neither anonymous nor lonely. God and "The Director" know who he is, where he lives, and what he does. And everywhere Harry goes he is now accompanied by his guilty conscience. Oh, Harry's got a lot of company. Or, as he tells his new fake girlfriend while listening to the tapes, "It's no ordinary conversation. It makes me feel -- something."

There aren't too many weaknesses. There's a murky dream sequence in which Harry describes his childhood paralysis, but it doesn't have too much to do with the person we know as an adult. Cazale is professional and sympathetic. Allan Garfield is a standout in a mostly comic role as Hackman's jealous rival, a blustery showman who pulls jokes on everyone including himself. The way he uses his blonde assistant in a tiny dress to help him display his wares at a buggery convention is hilarious. He's like an on-stage magician cracking jokes while he stuffs the doves up his sleeve. The party scene reminds me of "La Dolce Vita" when the party-goers explore the ancient castle. People inhabit vast empty echoing spaces. Most of the time they are blocked from one another by iron gratings or hanging sheets of plastic. They whisper intimacies to fantasies.

The score is fine. Carmine Coppola uses old melodies behind some of the scenes, and a tinkling puzzling piano statement behind most of the incidents. Sensibly the screen is left silent except for natural noises when Harry looks into the scene of the murder he thinks he witnessed.

You know, sometimes it's possible to read too much into something, to see Gestalts where there be no Gestalts. I don't know if I'm making something out of nothing, but is it a coincidence that Harry's birthday falls on the same day he develops a conscience? Or that on the same day, the Director's assistant offers him "Christmas cookies"? Is it pure chance that the repetitive song "Red Red Robin" contains the line, "Still I listen for hours and hours"? That the assistant's name, Stett, means "leave it alone" in Latin?

There's much more to be said about this film but I don't want to run out of space so I'll simply recommend seeing it. In its own quiet way it's a far more provocative movie than "The Godfather."