Dr. Louis Creed and his wife, Rachel, relocate from Boston to rural Maine with their two young children. The couple soon discover a mysterious burial ground hidden deep in the woods near their new home.
The Creed family – Louis, Rachel, Ellie, Gage, and cat Church – move from Boston to Ludlow, Maine. They befriend their neighbor Jud Crandall. After Church is killed by a truck, Jud brings Louis to the town’s Pet Sematary to spare Ellie the pain of losing him, which is inhabited by a spirit that can resurrect the dead, but bringing them back in a more sinister form. They bury Church there, and he returns more vicious. Louis tries to kill him but can’t do it, so he abandons him down the road.
On Ellie’s 9th birthday, she walks into the street when she sees Church and is killed when a truck swerves, and its tanker strikes her. Overcome with grief, Rachel leaves with Gage to her parents’ home while Louis digs up Ellie’s body and buries her in the Pet Sematary. She returns and is no longer the sweet girl she was in life, but a more grim and disturbed being.
After finding out what Louis did, Jud tries to kill Ellie before she does something terrible, but she gets to him first and kills him. Rachel and Gage return home to find the resurrected Ellie, who proceeds to attack her family. Louis brings Gage to safety, but Ellie kills Rachel and takes her body to the Pet Sematary. Before Louis can kill Ellie, Rachel returns and kills him first. They bring him back, and it is implied Gage will suffer the same fate.
The Creed family – dad Louis (Jason Clarke), mom Rachel (Amy Seimentz), young daughter Ellie (Jeté Laurence), toddler son Gage (Hugo and Lucas Lavoie), and pet cat Church (short for Winston Churchill) – move to the Maine countryside so that Louis can spend more time with his family. Ellie meets and befriends their elderly widowed neighbor Jud (John Lithgow), who has lived there his entire life. They learn that there is a “pet sematary” on their property, where the local kids bury their deceased pets. The woods beyond the pet sematary are blocked off by a large deadfall.
Louis, who works at the local college health center, witnesses a tragedy. A college student named Pascow is hit by a car and dies while Louis tries to keep him alive. Pascow’s spirit visits Louis and tells him, as thanks for trying to save his life, not to journey beyond the pet sematary. The incident causes Ellie to inquire about a death. Rachel prefers not to talk about death due to a traumatic experience in her past. While a young girl, Rachel was left to watch her ill and deformed sister Zelda. Despite being told not to do so, Rachel sends Zelda’s supper to her using a broken dumb waiter. When Zelda goes to get her dinner, she falls into the dumb waiter and is sent plummeting to her death.
One night, Louis and Jud find Church dead on the side of the road, having been run over by the trucks that pass on the major roadway running by Louis’ house. Jud, allegedly motivated by his desire to spare Ellie’s feelings, takes Louis and the corpse of Church beyond the deadfall and into the woods. The woods are home to a supernatural force. Louis buries Church in an ancient burial ground in the woods at Jud’s urging. The next day, a resurrected Church returns home. Though alive, Church exhibits aggressive behavior and murderous impulses (killing and eating small critters). Jud explains that the locals know of the burial ground beyond the pet sematary, but that nothing has ever come back the same (he also says that he believes anyone who visits the burial ground is compelled by evil forces to introduce it to others). Louis eventually abandons Church deep in the woods and tells Ellie that Church ran away.
On Ellie’s birthday, Gage toddles into the road as a truck barrels towards him. While Louis runs after Gage and catches him before he is struck, the truck skids out of control and strikes and kills Ellie (who was lured into the road by Church, who had made his way home). Louis sends Rachel and Gage away to her parents’ house. Realizing what Louis intends to do, Jud tries to stop Louis. But Louis drugs Jud, exhumes his daughter’s corpse, and buries her in the burial ground beyond the pet sematary. On his way there, he spots an evil wendigo in the woods.
The spirit of Pascow appears to Rachel and Gage and tells them to return home. Meanwhile, Ellie is resurrected returns home to Louis. She realizes that she died and has been resurrected, and exhibits a disturbing personality.
Jud awakens and discovers that Ellie has been brought back to life. He goes to his home to get a gun to “undo” what Louis has done, but is attacked and stabbed to death by Ellie. Rachel and Gage return home and Rachel cannot accept that this Ellie is the same one who died. Angered by her mother’s rejection, Ellie attacks. Louis manages to get Gage out of the house and secure him in his car seat, but Ellie stabs Rachel to death before she can also escape the house. With her dying words, Rachel begs Louis to make sure she isn’t resurrected. But Ellie sneaks up on Louis and knocks him out before dragging Rachel’s corpse into the woods.
When Louis awakens, he accepts that he must kill Ellie. He tracks her to the pet sematary where the pair fight. Louis gets the upper hand but, before he can kill his daughter, he is fatally impaled by a resurrected Rachel. The ghoulish mother and daughter than drag Louis’ corpse over the deadfall to the burial ground. The film ends with the resurrected bodies of Ellie, Rachel, Louis and Church returning home and approaching the car where Gage waits to greet his “family.”
The film starts with an overhead shot of a house on fire. We move to the house next door, which has a trail of muddy footprints leading up to the door, which has been stained with blood.
Dr. Louis Creed (Jason Clarke) is driving his wife Rachel (Amy Seimetz), kids Ellie (Jete Laurence) and Gage (Hugo and Lucas Lavoie), and Ellie’s cat Church, from Boston to their new home in Ludlow, Maine. Ellie admires the new home and goes around to explore.
While Louis goes to work at the university hospital, Ellie and Rachel spot a group of children with creepy animal masks orchestrating a procession for the deceased dog of one of the kids. Ellie wanders away from the house and comes across the pet cemetery (misspelled “sematary”). As she tries to climb a pile of logs, she is stopped by the Creeds’ new neighbor, Jud Crandall (John Lithgow). Ellie falls and gets stung by a bee. Jud helps pull the stinger out and rub dirt on it before Rachel comes looking for Ellie. After meeting Jud, he warns Rachel that the area can be a bit unsafe for kids. Later that night, Louis has a talk with Ellie about death and the afterlife. He later talks to Rachel about it and affirms his belief that there is nothing after death.
At the hospital, a young man named Victor Pascow (Obssa Ahmed) is brought in after a hit-and-run. His face is horribly mutilated with his brain exposed, terrifying the nurses. Louis does his best to revive Pascow, but he dies. Moments later, Pascow appears to revive before Louis and tell him something about a barrier that must not be broken. A nurse comes in, and Louis thinks he was just hallucinating, but he is still shaken for failing to save the man.
The next day, Ellie goes to bring a basket of cookies to Jud. She walks into his house and is found by him. She sees a picture of his late wife Norma (Suzy Stingl) and asks about her. Jud later has dinner with the Creeds as Ellie shows off her ballet skills.
Later, Louis has a vision that Pascow is calling out to him. Louis walks through a door and ends up in the woods. Pascow tells Louis he is trying to help him and then aggressively warns that the “ground is sour”. Louis is woken up by Gage, leading him to think that he was just having a crazy dream, until he sees under his sheets to find that his feet are covered in dirt.
On Halloween, Jud calls Louis to come see something. They find Church dead after being hit by a truck. They hide this from Ellie to spare her the heartbreak. Louis tells Rachel, who tells him that she feels she has been haunted since moving in. Since she was a child, Rachel has been traumatized by the death of her sister Zelda (Alyssa Brooke Levine), who suffered from spinal meningitis and would taunt Rachel about her ending up the same way. One night, the girls’ parents were out, and Rachel had to feed Zelda using the dumb waiter to raise her food up to her room, even though Rachel was warned not to do so since it gets stuck. Sure enough, it did just that, and when Zelda tried to get her food, she fell down the shaft, and Rachel saw her sister’s mangled body. It has left her feeling guilty ever since, and she doesn’t want Ellie to go through a similar feeling.
Louis goes with Jud to bury Church in the Pet Sematary, but Jud offers to help Louis so that Ellie won’t feel sad for her loss. They climb the log pile that Ellie tried to climb and walk further to a burial ground where they place Church.
The following morning, Louis and Rachel try to tell Ellie that Church ran away, but she tells him that he came back last night and is in the closet. To Louis’s surprise, she is correct, although Church is clearly not the same. Louis looks into the history of the grounds, while Ellie tries to play with Church. She tries brushing his fur but notices that it is knotted up, and that he smells bad. Church then scratches Ellie before running off. Later, while Louis and Rachel try to get intimate, Church brings a dead bird to the bed and starts gnawing at its stomach.
Louis later finds a drawing that Ellie says was made by Gage which is of a man being hit by a car and lying in a pool of blood, much like Pascow. He then goes to talk to Jud about Church returning. Jud tells him that the grounds are said to contain an entity known as the Wendigo that can bring things back from the dead, but they won’t come back the same. Louis then returns home to find Church in Gage’s crib after attacking and frightening the poor boy. Louis attempts to euthanize Church but can’t bring himself to do so when the cat momentarily appears to be his normal sweet self. He instead brings Church by the highway and leaves him so that he can just tell Ellie that he ran away.
The family throws a party for Ellie’s 9th birthday, but she is still missing Church. As the kids start playing, Ellie wanders off when she sees Church in the street. She walks up to him in the middle of the road, and Gage walks over to follow. Louis notices Gage in the street and runs to save him just as a truck heads their way. However, the truck driver swerves to avoid them, but the tanker he is carrying falls off and strikes Ellie, killing her. Rachel breaks down while Louis runs to his daughter’s body in utter devastation.
Ellie is laid to rest, and Rachel is so overcome with grief that she takes Gage with her to stay at her parents’ house. Jud later joins Louis outside by a campfire to grieve with him. Jud feels that he is to blame for Ellie’s death as he should have never shown Louis the burial grounds, feeling that there is a power to it that affects those who go near it. Jud knows what Louis is thinking of doing, but before he can try and convince him to do otherwise, he drugs Jud’s drink and waits until he passes out before heading out. Louis goes to the cemetery and digs up Ellie’s body, then goes to bury her beyond the Pet Sematary. Mere hours later, Ellie returns alive (mostly) to her house, and Louis embraces her. However, she now speaks with a monotone, her eye is disfigured from the accident, and she is able to remember the moments leading up to her death. Louis sleeps next to her, now slightly more unsettled.
At Rachel’s parents’ house, she is continuously haunted by Zelda, seeing her twisted body crawling toward her, and even having Rachel take her form. Meanwhile, Gage yells out Pascow’s name, apparently seeing him in visions as well. Rachel tries to get in touch with Louis, who manages to avoid telling her what he did. She ends up deciding to take an early trip back home after contacting Jud to say she hasn’t been able to reach Louis. At the same time, Ellie starts to grow increasingly disturbing, as she dances around the living room but begins to smash things in a rage. Jud goes to the Creed house to talk to Louis, where he lies about not hearing from Rachel, and he starts to look more and more insane. Jud knows what he did and tells him what he has to do now, which Ellie overhears.
Jud goes back home to get his gun when he hears something moving in the house. Ellie sneaks up on him and severs his Achilles tendon. Now crippled, Jud tries to go for his gun while Ellie taunts him and says he let Norma die. To drive the knife further, she takes Norma’s appearance to torment Jud. Ellie then proceeds to stab him to death.
Rachel and Gage return home. Just as Rachel goes to embrace Louis, Ellie walks in and horrifies her mother. Knowing that this is not her daughter, she runs upstairs with Gage. Louis goes over to Jud’s house for help but finds him dead. He runs back as Rachel is lowering Gage out the window to Louis as Ellie tries to break in. She does so and stabs Rachel in the abdomen. Rachel tells Ellie that her real daughter is dead, and Ellie delivers the fatal stab. She then drags Rachel’s body away.
Louis locks Gage in the car and goes to find Ellie. They find each other in the woods, and Louis realizes he has to kill Ellie. He tries to strangle her and then kills her with a shovel, but he hesitates when she acts like her old self again. Before he can do it, Louis is impaled through the chest by a resurrected Rachel. She and Ellie then drag Louis to the Pet Sematary.
It is now morning. The undead Creeds have burnt down Jud’s house. They walk up to the car, with Gage still inside, and Church shows up to leap onto the car. Louis walks up to his son, and Gage, none the wiser, unlocks the car.