Jake Gittes, a former cop who now specializes in divorce
investigations, meets a woman pretending to be the wife of Hollis
Mulwray, the chief engineer of the Los Angeles Water and Power Company. Claiming
that people have seen Hollis with another woman, she asks Jake to
investigate her husband’s alleged infidelity.
Jake begins his investigation by listening to testimony
at a public hearing for a proposed dam and reservoir. Though the
city is suffering through a drought, Hollis opposes the project,
sending the audience into an angry uproar. One man accuses Hollis
of being paid to steal water. Jake then trails Hollis, who spends
most of the day checking out the city’s water supplies. Later, Jake
takes photos of Hollis embracing a blond woman, which he gives to
his client. Without Jake’s knowledge, the newspaper prints the photographs
the next day.
This event brings the real Mrs. Evelyn Mulwray into his
office, where she threatens to sue Jake for ruining her husband’s
name. Jake attempts to find Hollis at his office but is instead
escorted out by the chief deputy engineer, Russ Yelburton, and his
assistant, Claude Mulvihill. Jake then drives to the Mulwray mansion
to convince Evelyn that he was set up along with her husband, and
she quickly agrees to drop the proposed lawsuit. When Jake demands
to talk to Hollis, Evelyn suggests he look for him at Oak Pass Reservoir.
By the time Jake arrives, the police have already discovered Hollis’s
drowned body in the empty reservoir. Later, Jake investigates a
dry riverbed where another drowning death occurred and meets a Mexican
boy who tells Jake that he once reported to Hollis about the periodic
flooding of the supposedly dry waterway.
That night, Jake returns to the reservoir where the police
found Hollis’s body. He hears two gunshots—the signal to open the sluice—and
jumps into an empty run-off channel for cover. Jake nearly drowns
when water comes coursing down the channel but manages to scramble
to safety. He then comes across Mulvihill, who threatens Jake for
trespassing. Mulvihill pins Jake’s arms back while an unnamed hoodlum
slices Jake’s nostril open with a knife and warns him to stay off
the case.
Later, Jake meets with Evelyn and accuses her of hiding
something. He tells her that Hollis was murdered because he discovered that
portions of the city’s water supply were being dumped into run-off
channels in order to create a drought and build support for the new
reservoir.
The next day, Jake returns to Yelburton’s office. There,
a secretary tells him that a man named Noah Cross once owned the
city’s entire water supply, but his business partner Hollis Mulwray
persuaded him to turn it over to the city. Jake accuses Yelburton
of arranging both the pictures and Hollis’s death. Yelburton denies these
claims, but suggests that some water is being diverted to irrigate
orange groves in the San Fernando Valley, outside of the city limits..
Jake then returns to his own office, where Evelyn officially hires
him to find out who killed her husband. Jake also reveals that he
knows her father is Noah Cross, a revelation that makes Evelyn visibly
nervous. Evelyn explains her nervousness by saying that her father
and Hollis had a falling out over the Water Department, but she
unintentionally hints that their disagreement may have had something
to do with herself as well.
Jake meets with Cross, who abruptly asks Jake if he has
slept with Evelyn, which he has not. Cross then probes Jake for
information, finally hiring him to find Hollis’s missing girlfriend.
Later, in the Hall of Records, Jake discovers that farmland is being
sold rapidly in the Valley’s drought area. Jake drives into the
Valley, where a farmer confesses that, rather than secretly irrigating
the farm, officials from the city regularly come in to poison his
water and blow up his tanks. Jake realizes that Cross and the land
speculators have been fabricating the drought in order to force
farmers into quickly selling their land at low prices. After the
dam Hollis opposed is built, the area will become fertile again
and Cross and the other new landowners will be able to sell the
land at an enormous profit.
Jake tells Evelyn Mulwray what he has learned about this scheme,
and the two discover that Cross and his associates at the Albacore
Club, a private association of the wealthy and powerful, are hiding
the scheme by purchasing the land in the name of the residents of
a local rest home of which they are benefactors. Returning to the
Mulwray home, Jake and Evelyn wind up in bed together. While lying
there,, Evelyn receives a phone call and leaves the house suddenly.
Jake secretly trails her to an unfamiliar house, where the young
blond woman he saw earlier with Hollis is lying on a bed, apparently
restrained. Jake confronts Evelyn about the woman, and Evelyn says
that she is her sister.
The next morning, Lieutenant Escobar of the Los Angeles
Police Department finds the fraudulent Mrs. Mulwray (an actress
named Ida Sessions) dead and accuses Jake of withholding evidence
that proves Evelyn killed her husband. Escobar tells Jake that Hollis
was found with saltwater in his lungs, suggesting that his body
was moved to the freshwater reservoir. Jake returns to the Mulwray mansion,
where he learns that a backyard pool is filled with salt water,
and he finds that it contains a pair of broken glasses. Jake deduces
that Evelyn drowned Hollis in the pond. He rushes to the house where
Evelyn is hiding her sister. There, he sees Evelyn packing hurriedly.
Jake calls the police and confronts Evelyn with his theory, showing
her the broken glasses.
Evelyn denies everything but finally confesses the secret
she’s kept throughout the movie: the blond girl, Katherine, is really
her daughter as well as her sister, the result
of an incestuous relationship Evelyn had with her father, Noah Cross.
Evelyn claims that Cross had Hollis killed because Hollis and Evelyn
tried to keep him away from Katherine. Evelyn points out that the
broken glasses were not Hollis’s, as Hollis did not wear bifocals,
and Jake deduces that they must have belonged to Cross. Jake decides
to help Evelyn and Katherine escape, suggesting they hide in Chinatown,
his former beat and the site of many bad memories for Jake. After
leading the police away from Evelyn’s true location, Jake arranges
for a former client to smuggle Evelyn and Katherine out of Chinatown
and into Mexico.
Jake arranges a final showdown with Cross at the Mulwray
mansion, showing him evidence of both the land grab and the murder. Mulvihill,
who accompanied Cross, holds a gun to Jake’s head and forces him
to lead them to Chinatown and the girl. Cross finds the pair on
the verge of escaping and pleads with Evelyn to hand Katherine over
to him. Instead, Evelyn pulls a gun on Cross, shooting him in the
arm before attempting to flee with Katherine in their car. The police,
ignoring Jake’s claims that Cross is the true criminal, fire on
the car and end up killing Evelyn. Cross then takes Katherine away,
and Lieutenant Escobar orders the stunned Jake to go home.
