Bill Denbrough and Mike Hanlon

Bill Denbrough and Mike Hanlon first meet during the apocalyptic rockfight in the Barrens in July 1958, when Mike, fleeing a brutal attack by Henry Bowers and his gang, stumbles upon the Losers' Club. Bill immediately accepts him into the group, and Mike's arrival completes the circle of seven children who will together face the entity terrorizing Derry. From that moment, their friendship is cemented by shared danger and a common purpose: to destroy It.

The Summer of 1958: Forging the Bond

Mike's integration into the Losers' Club is immediate and seamless. When he appears in the gravel-pit, bloodied and desperate, Bill does not hesitate to include him in the fight against Bowers. After the rockfight, Mike joins the others in the Barrens, and Bill asks him, "You w-w-want to heh-help?" with the same casual acceptance he offers any new member. Mike's presence is felt as a completion; Bill later reflects that "we're all together now," sensing that the group's power has been fully assembled. Together, they build the underground clubhouse, share stories of their encounters with the shape-shifting monster, and participate in the smoke-hole ceremony, where Bill and Mike are the last two to remain conscious, sharing a vision of It's arrival on Earth eons ago. This shared ordeal deepens their trust and mutual reliance.

The Adult Reunion: Mike as the Catalyst

Twenty-seven years later, Mike, who has remained in Derry as the town librarian, is the only one of the Losers who remembers the summer of 1958 and the promise they made. He has spent years researching Derry's history and tracking the cycle of violence that recurs every twenty-seven years. When the murders begin again in 1984-85, Mike makes the decision to call his childhood friends back to Derry. He calls Bill first, and Bill, who had forgotten everything about his childhood, experiences a sudden, jarring return of memory upon hearing Mike's voice. Mike's call is the trigger that sets the entire final confrontation in motion. During their reunion lunch at the Jade of the Orient, Mike lays out the evidence of the new killings and the town's dark history, and it is Bill who calls the question: "Do we stay and fight or do we forget the whole thing?" Bill's vote to "kill It" is the first, and the others follow, with Mike raising his hand in solidarity.

The Final Confrontation and Aftermath

In the final battle under Derry, Mike is gravely wounded by Henry Bowers, who has escaped from Juniper Hill and attacked him in the library. Bill and the others feel Mike's peril through their psychic connection and send him their power, enabling him to fight off his attacker. After It is destroyed, Bill visits Mike in the hospital, where Mike is recovering from his wounds. Their conversation reveals the gradual forgetting that is already beginning to take hold. Mike tells Bill that he has kept a notebook of everything that happened, but even the names and addresses in his address book are fading. Bill, in turn, shares his plan to try to save his catatonic wife, Audra, by taking her on a bike ride. Their final exchange is one of quiet understanding and mutual support. Mike offers Bill the use of his house, and Bill kisses Mike's cheek before leaving, a gesture of deep affection and gratitude. In the epilogue, Mike's diary entries show his love for his friends and his acceptance of the forgetting, while Bill, having successfully revived Audra, leaves Derry with her, the memory of his friends already beginning to slip away.