: Seven friends come into confrontation with an otherworldly creature that feeds on children's fears, but they fail to destroy it. Having matured, friends again encounter the creature and destroy it.
Part one. A shadow of the past
The summer of 1958. The small town of Derry in Maine is terrorized by a mysterious serial killer, killing children with inhuman cruelty. Seven eleven-year-olds - Ritchie Tosier, Bill Denbro, Beverly Marsh, Mike Hanlon, Eddie Kaspbrack, Ben Hansky and Stan Uries - face each mysterious evil - a terrifying monster that can take any form.
Joining together in the Club of Losers, the children decide to find and destroy the monster that they call It. The leader of the Losers is Bill Denbrough, whose brother It killed a year ago.
No good friends. No bad friends. There are only people with whom you want to be with whom you need to be with, who have settled in your heart.
In addition to the monster, the Losers are pursued by the local bully Henry Bowers with his friends, which unites friends even more.
The confrontation makes the "Losers" realize a lot. None of the adults can help them: ceasing to be children, adults are not able to imagine that the killer is not a person, they cannot even see It.Looking at their hometown in a new way, “Losers” understand that their union is more than just the friendship of seven children.
The fight against the creature, which exists in two dimensions at the same time, ends in the sewers deep beneath Derry. There, in the monster's den, the children give him a fight. Having received serious, but not fatal wounds, It runs away and hibernates.
"Losers" find that they hopelessly got lost in the maze of pipes, and their strong connection begins to break down. To restore it, they have group sex with Beverly, and later they swear that if someday the monster returns, they will again confront it. Returning to normal life, the children forget what happened, forget about each other and eventually leave Derry.
Part two. June 1958
27 years pass by. In the summer of 1985, Derry was again shocked by a wave of horrific killings. Mike Hanlon, the only one who remained in Derry, understands that It has returned and reminds the "Losers" of the oath given in childhood. For six rich, respectable Americans, the return of childhood nightmares is a shock.
Only five find the strength to return to Derry and continue the fight: Stan Uries commits suicide immediately after talking with Michael. Having united again, adult “Losers” begin to restore bit by bit their childhood memories. Moreover, each of them again encounters Ono.
Monsters live by our faith.
Seized with a thirst for revenge, It involves new participants in its diabolical game: an adult Henry Bowers who escaped from a psychiatric clinic seriously injures Mike Hanlon, and distraught husband Beverly Marsh kidnaps Bill Denbro's wife.
Five surviving "Losers" again descend into the sewers, this time to destroy the monster completely. The battle with the monster in the dungeons turns on the surface with a hurricane and flood, which leads to the partial destruction of the city of Derry. At the cost of Eddie Caspbork's life, The Losers succeed in defeating It.
Like 27 years ago, returning to normal life, the Losers again forget about what happened and leave Derry. But this time everything happens much faster. Mike Hanlon, having discovered that the names of the friends with whom he spoke a few days ago, disappeared not only from his memory, but also from his notebook, he realizes that his mission has been fulfilled and It has been destroyed forever.
