In the novel It, the creature is ultimately defeated when its heart is destroyed by Bill Denbrough, after a determined pursuit and a crucial act by Ben Hanscom to prevent its potential return.
The final confrontation unfolds after It, injured from an earlier encounter, attempts to retreat and recover. However, members of the Losers' Club — Bill, Richie, and Ben — relentlessly chase after the wounded entity. During their pursuit, they discover a horrifying revelation: It has laid eggs, a clear sign of its terrifying reproductive capability and a potential threat to return in the future.
The climax of the novel's ending involves several critical actions:
- Destruction of the Eggs: Ben Hanscom courageously stays behind to destroy the eggs It had laid. This vital act prevents the creature from perpetuating its lineage and ensures that the cycle of fear and death it inflicted upon Derry could truly end.
- Final Confrontation: While Ben tackles the eggs, Bill Denbrough and Richie Tozier press on, heading directly toward their ultimate confrontation with It.
- The Heart of It: Bill Denbrough, driven by courage and a deep understanding of the creature's true form, fights his way into It's physical manifestation. He manages to locate It's heart, the core of its being, and successfully destroys it. This act of profound bravery and resolve leads to the definitive end of It's reign of terror.