Pet Sematary Louis Creed is a doctor who moves his family to Ludlow, Maine from Chicago because of a job he accepted as an MD at some University. His family (Rachel, his wife, Ellie, his daughter, and Gage, his baby son) are happy about moving, thought they soon will come to have reservations. Both children are hurt on the first day of the move. Louis makes friends with an old man across the road named Jud Crandall, who promises to show them where the path behind their house leads. It is with these three seemingly innocuous events that the spiral in toward darkness begins.

The path behind the house ends up in a place known to the locals as the Pet cemetery. It is a graveyard for children's pets, most lost to the Interstate Road which separates the Crandall's and the Creeds' homes. The gravestones are set in a spiraling pattern. Ellie has questions about death terrified that her cat Church will have to go to the Pet cemetery.

Louis answers her honestly and later Rachel and him have an argument. She was Scared by the cemetery, and was uncomfortable with the idea of death in general because at the age of eight Rachel witnessed her sister Zelda die of spinal Problems, an incident which scarred her for life. It only gets grimmer from here. Louis's first day as a university MD is a horror.

A guy named Victor Pasco w is run over by a car. Before he dies he gives Creed an message warning him about the Pet cemetery and the grounds beyond. During Thanksgiving vacation, while Louis's family is away, the cat Church is killed by a truck. Jud offers to help Louis, and brings him to the Pet cemetery. They arrive at the Micmac Indian burial grounds. Jud has Louis bury Church and build a stone cairn over the grave.

Slowly Louis realizes the cairns are arranged in a spiral, like the markers at the Pet Sematary. Later, when Louis is home alone, Church returns. The burial grounds make the dead come to life, but it has greater powers as well. It is a dark and secret place, a place which actually control ls matters of life, death, and obsession.

After Church the cat returns he smells bad and acts vicious towards people. When the family returns they decide to go to the park for a picnic. Their little boy Gage dies by getting run over on the same road Church had been run over by. Louis, becoming very sad more and more obsessed with the memory of the burial grounds, decides to bring him back to life. Against Jud's stern warnings, he unearths his son and renters him at the burial ground.

Gage comes back, possessed by the dark spirit of the Micmac ground and of death. He kills Jud and Rachel and tries to kill Louis but Louis kills him. Louis goes mad because of Rachel death. Trying one more time for salvation, he buries Rachel at the grounds and pays the price.