The Grudge describes a curse that is born when someone dies in the grip of a powerful rage or extreme sorrow (see Onryō). The curse gathers in the place where that person died. Those who encounter this murderous supernatural force die and the curse is reborn repeatedly, passed from victim to victim in an endless, growing chain of horror. The following events are explained in their actual order (which differs from the order shown on film).
The film opens on a man, Dr. Peter Kirk (Bill Pullman) - An American Professor in Japan's Capital, Tokyo. One morning, he is standing on his high rise balcony, with a troubled look on his face. His wife, Maria (Rosa Blasi), looks at him from inside their apartment and asks him what's wrong. Without any word or hesitation, he flings himself over the balcony, committing suicide, as a shocked Maria looks on.
The Williams Family
Matthew Williams (William Mapother), his wife, Jennifer (Clea DuVall), and his ailing mother, Emma, move into the Saeki house. Jennifer is unhappy with her life in Japan; she is unable to speak the language, and has gotten lost once on a walk. Matthew assures her things will improve and that if they don't, the family will return to the United States.
Jennifer falls asleep on a couch in the living room. The sound of her bowl hitting the floor startles her awake and she discovers the bowl on the floor, the contents strewn everywhere. She scolds Emma for making the mess, but then sees a trail of wet child's footprints leading out to the hall. She sees a cat on the landing of the stairs and sees a pair of white arms gently pick it up. She continues upstairs and enters her bedroom (Toshio's former bedroom). The door closes behind her.
Matthew returns from work and finds the house in complete disarray with trash strewn everywhere. He calls out to his wife, who doesn't answer. He finally finds her on their bed, unable to move or speak and struggling to breathe. Before he can call an ambulance, he is startled by the sudden appearance of a young boy making cat sounds named Toshio (Yuya Ozeki). He backs up against the closet as Toshio appears suddenly over his head.
Later, Susan, Matthew's sister, is preparing to leave the office. After attempting to call, Susan increasingly becomes concerned from not being able to reach Matthew. She starts to leave her office building but she is stopped by the sound of moaning coming from the hallway. She quickly exits to the stairs but is frightened when the lights start to flicker and shatter. Susan looks over the railing to see Kayako's ghost (Takako Fuji) crawling up the stairs. Susan flees to the closest hallway but Kayako grabs her cell phone charm and pulls it off. Susan goes to the security office, seeking help. There, the security guard promises to check it out. Susan watches the monitor as the security guard investigates. However, he finds nothing and leaves. Then, the lights flicker and Kayako rises up out of the shadows in the hallway and walks toward the security camera. Susan runs.
Susan takes a taxi cab back to her apartment. She enters an elevator, and it ascends several floors. Susan does not notice, however, that Toshio is standing outside each set of elevator doors she passes, getting progressively closer with each passing floor. Susan makes it safely inside when her phone rings. It is Matthew claiming to have forgotten his apartment number and asking to be buzzed inside. She tells him where to find her and activates the buzzer with the phone. The doorbell rings immediately after she hangs up. Thinking Matthew could not possibly have had time to arrive, she checks the peephole of the door. Shocked to find it is Matthew, Susan believes he is pranking her. She angrily throws open the door, but no one is there. The death rattle emanates loudly through the phone in Susan's hand. She drops and breaks the phone, yet the rattle can still be heard. Cowering in bed, Susan reaches beneath the covers and pulls out the rabbit's foot phone charm from her phone and drops it in fear. A lump billows from underneath the covers and moves toward Susan. She lifts the sheets, seeing Kayako's face. She is abruptly pulled under and both disappeared.
The Social Workers
(The events in this section are shown throughout the film, though they take place in time shortly after the Williams' move in to the house.) Yoko (Yoko Maki) is a girl whose work is to take care of Emma and clean the house. While picking up trash on the floor and stairs, she hears someone walking around up in the attic. Following the noise, Yoko enters a closet in the bedroom and sees a small door in the ceiling, which leads to the attic. Using a lighter, Yoko sticks her head up through the door and slowly turns around, looking for the source of the sound. She eventually comes face to face with the onryo which Kayako Saeki has now become, who attacks her, dragging her up into the closet.
Karen Davis (Sarah Michelle Gellar) is then called in to work at the house (in Setagaya) and care for Emma after Yoko disappears. While working, Karen finds a closet that's been taped shut with cat-like noises coming from it. When she rips off the tape and opens the door, she finds a little boy (Toshio). The boy refuses to come downstairs so she asks him for his name. "Toshio," he says, in a toneless, eerie voice. Emma begins stirring and muttering in the other room. As Karen calms her, a dark shadow of hair emerges from a corner of the room, terrifying Emma. Karen looks up to see Kayako reaching for Emma. Kayako's hair, which was covering her face, flies back to reveal the whites of her eyes. The irises roll into place and focus on Karen as she backs away in fright.
Alex, Karen's boss, finally arrives to find Emma unconscious and Karen in a state of shock. Karen is taken to the hospital while detectives question Alex. Detective Nakagawa (Ryo Ishibashi) asks Alex about the people that lived there, and tell him that Yoko has been missing from work. The detectives notice that the phone handset is missing from the cradle and push the page button. They trace the sounds to the attic where they discover the corpses of Matthew and his wife. They also make the grisly discovery of a human jaw and wonder to whom it belongs and where the rest of the body might be. Later in the movie, Yoko is spotted again by Alex as she is shuffling down the stairs of the caretaking facility where Alex, Karen, and Yoko work. As he is walking towards her, he accidentally slips on a liquid, which he discovers is blood when he touches it. Alex calls out repeatedly to Yoko, who does not answer in any way until she reaches the bottom of the stairs. She then turns around to reveal her face,as Alex screams in horror and dies, her face is shown to now be horribly disfigured without her lower jaw and tongue hanging out, and the screen fades to black.
Karen tells her story to detectives, emphasizing the appearance of a boy. Over the next few days, she is constantly tormented by Kayako, in her shower, on a bus (while with Jack), etc. Frightened but determined, she starts research on the history of that house on the Internet by searching in Google. Eventually, she learns of the murders from the website of a Japanese Newspaper. On the same page, she also comes across the news of death of the American Professor, Dr. Peter Kirk. She now decides to know the entire history from Dr. Kirk's widow, Maria Kirk.
Detective Nakagawa becomes convinced that the rash of deaths and missing people is connected to the house when he views the entire security video taken at Susan's office building. He watches as Kayako proceeds down the hall, then to come face to face with the camera as the video fuzzes out. He then returns to the Saeki House with two cans of gasoline. He is distracted by sounds of Toshio drowning in the bath tub. He enters and finds a boy hanging out of the tub, and tries to revive him. His eyes snap open, and Takeo (Takashi Matsuyama) appears behind him. Nakagawa only has time to turn around before Takeo shoves him into the bathtub and drowns him like Toshio.
Karen questions Maria Kirk, Peter's widow, who does not appear to know anything about the house, its occupants, or why her husband committed suicide. She allows Karen to search through old photos. Karen discovers a living Kayako in the background of every photograph, clearly following the couple. Karen then attempts to go talk with her boyfriend, Doug (Jason Behr), at their apartment. However, she discovers he has gone looking for her after his own investigation. Karen then returns to the house in search of Doug.
Inside the house, Karen experiences a flashback of Peter Kirk's visit. It is revealed that Kayako was once a student of Professor Peter Kirk, and had become enamored with him. Kayako's husband, Takeo, discovered her obsession and in a fit of rage murdered her and their son, Toshio. This is the stain, the 'grudge' (onryo) of the house. Karen's flashback shows Peter discovering their bodies at the house. Overwhelmed by the brutality of Takeo's assassination of Kayako, Karen staggers downstairs and the house returns to the present time. Doug grabs her ankle before she leaves. He is incapacitated, and she tries to drag him to the door. A door opens upstairs. The onryo which Kayako has now become crawls down the stairs toward them, and gives Doug the kiss of death. Karen opens the door, but Kayako's ghost is suddenly there. She slams the door and kicks over one of the gas cans. She takes Doug's lighter and tosses it onto the gas as Doug suddenly becomes Kayako. The screen goes white. (In the director's cut, there are shots of Karen being put into an ambulance van).
At the hospital, Karen learns that the house was saved from burning and mourns Doug's dead body. Suddenly, Kayako's hair and arm comes from beneath the sheet that covers him, but Karen realizes that it's just her imagination (when the hands turn normal). Kayako then appears behind Karen. As Kayako utters her death-rattle, the movie ends with an eyeshot of her.