It is a 1986 horror novel by American author Stephen King. It was his 22nd book and his 17th novel written under his own name. The story follows the experiences of seven children as they are terrorized by an evil entity that exploits the fears of its victims to disguise itself while hunting its prey. "It" primarily appears in the form of Pennywise the Dancing Clown to attract its preferred prey of young children.
The novel is told through narratives alternating between two periods and is largely told in the third-person omniscient mode. It deals with themes that eventually became King staples: the power of memory, childhood trauma and its recurrent echoes in adulthood, the malevolence lurking beneath the idyllic façade of the American small town, and overcoming evil through mutual trust and sacrifice.
King has stated that he first conceived the story in 1978, and began writing it in 1981. He finished writing the book in 1985. He also stated that he originally wanted the title character to be a troll like the one in the children's story "Three Billy Goats Gruff", but who inhabited the local sewer system rather than just the area beneath one bridge. He also wanted the story to interweave the stories of children and the adults they later become.
The novel won the British Fantasy Award in 1987, and received nominations for the Locus and World Fantasy Awards that same year. Publishers Weekly listed It as the best-selling hardcover fiction book in the United States in 1986. It has been adapted into a 1990 two-part miniseries directed by Tommy Lee Wallace, a Hindi 1998 television series directed by Glen Baretto & Ankush Mohla, and into a film duology directed by Andy Muschietti; It was released in September 2017 and It Chapter Two was released in September 2019.
During a rainstorm in Derry, Maine, a six-year-old boy named Georgie Denbrough sails a paper boat along the rainy streets before it washes down into a storm drain. Looking in the drain, Georgie encounters a clown who introduces himself as Pennywise the Dancing Clown. Georgie is enticed by Pennywise to reach into the drain and retrieve his boat, where the clown rips his arm off, leaving him to die.
The following June, an overweight eleven-year-old boy named Ben Hanscom is harassed by a bully named Henry Bowers and his gang on the last day of school, escaping into the marshy wasteland known as the Barrens. There, Ben befriends an asthmatic hypochondriac named Eddie Kaspbrak and "Stuttering Bill" Denbrough, Georgie's elder brother. The three boys later befriend fellow misfits Richie Tozier, Stanley "Stan" Uris, and Beverly Marsh, and refer to themselves as "The Losers Club". As the summer draws on, the Losers each encounter Pennywise in terrifying manifestations: a mummy on a frozen canal to Ben, a fountain of blood (that only children can see) from Beverly's sink, a rotting leper to Eddie, drowned corpses to Stan, and a frightening phantom of Georgie to Bill. Meanwhile, an increasingly unhinged and sadistic Bowers begins focusing his attention on his African-American neighbor Mike Hanlon and his father. Bowers kills Mike's dog and chases the terrified boy into the Barrens, where he joins the Losers in driving Bowers' gang off in a rock fight, a humiliated Bowers vowing revenge. Mike becomes a member of the Losers Club after revealing his own encounter with Pennywise in the form of a flesh-eating bird. From Mike's historical scrapbook, the Losers realize that "It" is an ancient monster with a hold on the town. Following further encounters, the Losers construct a makeshift smoke hole that Richie and Mike use to hallucinate It's origins as an ancient alien entity that came to Earth, beginning a cycle of feeding on children for a year followed by a 27-year-long hibernation.
Soon, Eddie is hospitalized by Bowers and several of his friends, and Beverly witnesses one of the bullies, Patrick Hocksetter, kidnapped by It in the form of a mass of flying leeches. The Losers discover a message from It in Patrick's blood, warning them that It will kill them if they interfere. In hopes that silver can wound It, Ben makes two silver slugs out of a silver dollar, and the Losers enter an abandoned house where Eddie, Bill, and Richie had previously encountered It to attempt to kill It. They manage to wound It with the silver while It is in the form of a werewolf. Deeming the Losers a threat, It manipulates Bowers into murdering his abusive father and chasing the Losers into the sewers to kill them, where his accompanying fellow bullies, Victor "Vic" Criss and Reginald "Belch" Huggins, are both killed by It, and Bowers becomes lost in the sewers, traumatized.
In the sewers, Bill performs the "Ritual of Chüd" in an attempt to face It in the Macroverse, the alternate universe where It is from, where he meets the monster's antithesis Maturin, an ancient turtle that created the universe. Bill learns that It can only be defeated during a battle of wills, and sees It's true form, the "Deadlights", before Bill defeats the monster with Maturin's help. After the battle, not knowing if they killed It or not, the Losers get lost in the sewers until Beverly has sex with each of the boys to bring unity back to the group. The Losers then swear a blood oath to return to Derry should It resurface. Bowers, having lost his sanity by the time he washed out of the sewers into a nearby river, is institutionalized after being blamed for the town's child murders.
In July 1984, three youths brutally attack a young gay man named Adrian Mellon and throw him off a bridge, where both a bully and Adrian's boyfriend see a clown then appear. Adrian is found mutilated, and the teenagers are arrested and charged with his murder.
When a string of violent child killings begins in Derry again, an adult Mike Hanlon, now the town's librarian, calls up the six former members of the Losers Club and reminds them of their childhood promise to return should the killings start again. Bill is now a successful horror writer living with his actress wife, Audra; Beverly is a fashion designer, married to an abusive man named Tom Rogan; Eddie runs a limousine rental company and has married a hysterical codependent woman similar to his hypochondriac mother; Richie Tozier is a disc jockey; Ben Hanscom is now thin and a successful but lonely architect; and Stan Uris is a wealthy accountant. Prior to Mike's phone calls, all of the Losers had completely forgotten each other and the trauma of their childhood, burying the horror of their encounters with It. All of the Losers agree to return to Derry, except for Stan, who kills himself in terror of facing It again.
The Losers meet for lunch, where Mike reminds them that It awakens once roughly every 27 years for 12–16 months at a time, feeding on children before going into slumber again. The group decides to kill It once and for all. At Mike's suggestion, each person explores different parts of Derry to help restore their memories. While exploring, Eddie, Richie, Beverly, and Ben are faced with manifestations of It (Eddie as Belch Huggins and childhood friends in leper and zombified forms, Richie as a Paul Bunyan statue, Beverly as the witch from Hansel & Gretel in her childhood home, and Ben as Dracula in the Derry Library). Bill finds his childhood bicycle, "Silver," and brings it to Mike's. In the meantime, Audra, who is worried about Bill, travels to Derry; Tom arrives as well, intending to kill Beverly; and Henry Bowers escapes from the mental asylum with help from It.
Henry confronts Mike at the library, but Mike escapes alive. It instructs Henry to kill the rest of the Losers, but Henry is killed when attacking Eddie. It then appears to Tom and orders him to capture Audra, bringing Audra to It's lair, where Audra becomes catatonic, and Tom drops dead in shock. Bill, Ben, Beverly, Richie, and Eddie learn that Mike is near death and realize they are being forced into another confrontation with It. They descend into the sewers and use their strength as a group to "send energy" to a hospitalized Mike, who fights off a nurse that is under the control of It. They reach It's lair and find that It has taken the form of a giant spider. Bill and Richie enter It's mind through the Ritual of Chüd, but they get lost in It. Eddie injures It by spraying his asthma medication down It's throat, but It bites off Eddie's arm, killing him. It runs away to tend to its injuries, but Bill, Richie, and Ben chase after and find that It has laid eggs. Ben stays behind to destroy the eggs, while Bill and Richie head toward their final confrontation with It. Bill fights his way inside It's body, locates It's heart, and destroys it. The group meets up to head out of It's lair, and although they try to bring Audra and Eddie's bodies with them, they are forced to leave Eddie behind. They realize that the scars on their hands from their blood pact have disappeared, indicating that their ordeal is finally over.
At the same time, the worst storm in Maine's history sweeps through Derry, and the downtown area collapses. Mike concludes that Derry is finally dying. The Losers return home and gradually begin to forget about It, Derry, and each other. Mike's memory of the events of that summer also begins to fade, as well as any of the records he had written down previously, much to his relief, and he considers starting a new life elsewhere. Ben and Beverly leave together and become a couple, and Richie returns to California. Bill is the last to leave Derry. Before he goes, he takes Audra, still catatonic, for a ride on Silver, which awakens her from her catatonia, and they share a kiss.