Eleven-year-old Dawn Wiener is a shy, unattractive, unpopular seventh grader living in a middle-class suburban community in New Jersey. Her 17-year-old brother Mark is a nerdy, snooty high school student who plays clarinet in a garage band and shuns girls in order to prepare for college. Dawn's younger sister, 8-year-old Missy, is a spoiled, manipulative little girl who pesters Dawn and dances happily all around the house in a tutu. Their mother is a shrewish, overbearing woman who dotes on Missy and always sides with her in disputes with Dawn. Their father is a meek, immature, selfish man who always sides with Dawn's mother in her arguments with Dawn. Dawn's only friend is an effeminate fifth-grade boy named Ralphy, with whom she shares a dilapidated clubhouse in her backyard.
12-year-old Josh Baskin, who lives with his parents and infant sister in Cliffside Park, New Jersey, is told he is too short for a carnival ride called the Ring of Fire, while attempting to impress Cynthia Benson, an older girl. He puts a coin into an unusual antique arcade fortune teller machine called Zoltar Speaks, and makes a wish to be "big". It dispenses a card stating "Your wish is granted", but Josh is spooked to see it was unplugged the entire time.
Sean Randall (Connor Jessup), a goth teenager, is a friend of classmate Deanna (Alexia Fast), with whom he rides the bus every day. Her boyfriend plays in an ice hockey team and she is friends with the team's other members. Sean's father has a gun collection, and Sean sometimes joins him when he goes hunting. Sean films his father shooting a deer and show the footage to his schoolmates, which (when combined with his goth fashion sense) makes them think that he is creepy. The members of the hockey team bully Sean for being weird and for being friends with Deanna, which angers Sean.
Kevin, surnommé "Bouboule", pèse 100 kilos à l'âge de douze ans et n'a pas vraiment d'avenir. Souffre-douleur de deux garçons du quartier, il s'empiffre de frites, de pâtisseries et semble n'attendre qu'une crise cardiaque. Sa rencontre avec un vigile, Patrick, est déterminante pour la suite de sa vie...
In 2002, six-year-old Mason, Jr. (Ellar Coltrane) and his older sister Samantha (Lorelei Linklater) live with their single mother Olivia (Patricia Arquette) in Texas. Mason overhears Olivia arguing with her boyfriend, saying she has no free time. Olivia then moves the family so she can attend the University of Houston, complete her degree, and get a job.
Sieger is a fifteen-year-old boy, living with his widowed father, Theo, and his brother, Eddy, who, burdened with his mother's death, clashes with and acts out against his father. Along with his best friend, Stef, he is a member of the local athletics team. They—and two other boys, Tom and Marc—are chosen to represent the team at the national championship relay race. In order to win, they must train intensively.
A lonely boy named Michael Brower (Edward Furlong) lives an isolated existence in his absentee father's mansion. Michael's mother was killed in a car accident, which also permanently injured his leg. He spends his spare time stalking his crush, a typical girl-next-door named Kimberly. A huge fan of horror films and video games, Michael's only friend is a similar-minded misfit named Kyle. Kyle tells Michael about a new, ultra-realistic game called Brainscan. Intrigued, Michael sends away for the first disc.
Four friends — Chloe (Skyler Shaye), Yasmin (Nathalia Ramos), Sasha (Logan Browning), and Jade (Janel Parrish) — are about to start high school. Self-centered Meredith Eilazbeth Vickrica Baxter Dimly (Chelsea Kane) wants everyone to belong to a clique, and goes about organizing people. She does not like the independent spirit of the four girls and plots to destroy their friendship and make them conform to her pre-fabricated cliques. Chloe is an amazing soccer player. She meets Cameron (Stephen Lunsford) and is instantly smitten. Sasha is recruited as a cheerleader. Jade joins the science kids and meets Dexter (Chet Hanks) and designs great outfits. Yasmin joins journalism, even though her real passion is singing even though she hasn't realized yet. She also feels lonely as her friends are busy with their own cliques. She also meets Dylan (Ian Nelson), who is deaf but can lip read. The friends begin to drift apart, as they are compelled to stay within their cliques. Two years later, when an accidental food fight causes them to get detention, they realize that they miss being BFFs and decide to be friends again. They also try to get the other schoolmates to socialize outside their cliques, but their attempts fail when Meredith's 2nd Super Sweet 16 party (which ends disastrously) has them seated with their original cliques. The upcoming talent show and its prize of a scholarship gives them the idea to bring all the cliques together again with an act, but the chances are slim with Meredith's constant attempts to steal the spotlight. In the end, there is a tie. Meredith gets the trophy, but the girls get the scholarship, which they later give to Cloe.
On Saturday, March 24, 1984, five students report at 7:00 a.m. for all-day detention at Shermer High School in Shermer, Illinois. While not complete strangers, each of them comes from a different clique, and they seem to have nothing in common: the beautiful and pampered Claire Standish, the state champion wrestler Andrew Clarke, the bookish Brian Johnson, the reclusive outcast Allison Reynolds, and the rebellious John Bender.
Frank (Jon Foster) is an active member of fictional fraternity Sigma Zeta Chi, and hazes pledges for initiation by forcing them to believe they are going to rob convenience stores. Adam (Trevor Morgan) and Kevin (Lou Taylor Pucci) are pledges who go with Frank to rob the stores. Before they enter the store, another active brother gives them the money and reveals it was a break designed to test their bravery. However, due to confusion over which stores to stop pledges, Kevin is not stopped and actually tries to rob the store; Kevin is shot in the shoulder as a result. Frank finds out of the mix-up and attempts to stop Kevin but is too late. With Adam's help, he subdues the store clerk, Mike (Arlen Escarpeta), who is a high school friend of Adam. They return to the fraternity house and clear a party to take care of Kevin's wounds, but Frank orders Adam and Graham (Luke Sexton) to go back to the store, recover the security tape, and check on Mike. When returning to the store, they find that the security camera does not work, but Mike is reluctant to tell the police a lie to cover their tracks.
Ali Willis (Bijou Phillips) and Lisa Connelly (Rachel Miner) are friends with Bobby Kent (Nick Stahl) and Marty Puccio (Brad Renfro). They all go out on a double date. While in a parked car, Ali performs oral sex on Bobby, while Lisa and Marty have sex in the back seat. Lisa later learns she is pregnant, but is afraid that the child is Bobby's instead of Marty's, since Bobby raped her after beating Marty unconscious. Bobby emotionally and physically abuses Marty, and also rapes Ali. Lisa eventually proposes that they murder Bobby. Ali recruits her new boyfriend, Donny (Michael Pitt), and her friend, Heather Swallers (Kelli Garner), while Lisa recruits her cousin, Derek Dzvirko (Daniel Franzese). After doing drugs and having sex, the teens make their first attempt, but back out. Realizing they need help, they hire a supposed "hitman", Derek Kaufman (Leo Fitzpatrick), who is just a tough-talking adolescent.
Sampson (Robert Englund) and his son Ainsley (Joshua Leonard) are fishing in a swamp. While Ainsley is urinating, Sampson falls silent; Ainsley goes to see where he is and finds Sampson's corpse. He quickly grabs his harpoon, only to be murdered by an unknown monstrous being.
Zac was born on Christmas in 1960. He had a special relationship with his father Gervais, but things began to fall apart as Zac's non-masculine ways started to show. Their unique relationship officially came to an end when Gervais comes home to find Zac dressed in his mother's clothes. Ever since then, he "had unwittingly declared war on his father".
À Derry, dans le Maine, sept enfants ayant du mal à s'intégrer se sont regroupés au sein du « Club des Ratés ». Rejetés par leurs camarades, ils sont les cibles favorites des gros durs de l'école. Ils ont aussi en commun le fait d'avoir éprouvé leur plus grande terreur face à un terrible prédateur métamorphe qu'ils appellent « Ça ». Car depuis toujours, Derry est en proie à une créature qui émerge des égouts tous les 27 ans pour se nourrir des terreurs de ses victimes de choix : les enfants. Bien décidés à rester soudés, les Ratés tentent de surmonter leurs peurs pour enrayer un nouveau cycle meurtrier. Un cycle qui a commencé un jour de pluie lorsqu'un petit garçon poursuivant son bateau en papier s'est retrouvé face-à-face avec un clown répondant au nom de Grippe-Sou.
En 1989, sept enfants ont réussi à échapper à « Ça », une créature métamorphe dévorant les enfants de Derry. Vingt-sept ans plus tard, Bill Denbrough et ses amis reviennent à Derry à la suite de l'appel de Mike. Ils vont devoir à nouveau combattre le sinistre clown « Ça », qui s'est réveillé et recommence à se nourrir d'enfants. Lorsqu'ils reviennent à Derry, ils découvrent la véritable histoire de « Ça » et comptent bien l'achever une bonne fois pour toutes.