As Paul Edgecomb sits in a Louisiana assisted-living facility, a wave of nostalgia washes over him while he watches Top Hat. His companion, Elaine, becomes alarmed upon seeing the tears streaming down his face. He confides in her that the classic film has reopened a floodgate of memories from his time as an officer on the infamous "Green Mile" death row at Cold Mountain Penitentiary.
Back in 1935, Paul supervised a team of corrections officers, which included Brutus "Brutal" Howell, Dean Stanton, Harry Terwilliger, and Percy Wetmore, who was a direct report to Warden Hal Moores. Percy, leveraging his connection as the nephew of the governor's wife, relished his power to inflict suffering on the inmates, notably targeting Eduard "Del" Delacroix. He thrived on the sadistic pleasure derived from his cruel punishments.
The officers also faced the unending turmoil caused by William "Wild Bill" Wharton, a volatile inmate who frequently assailed them and hurled racial slurs at John Coffey, a gigantic yet kind-hearted black man wrongfully sentenced for the violent crime of murdering two white girls. However, as Paul learns more about John, he is astounded to discover the extraordinary healing abilities hidden within this seemingly ordinary man. After John effortlessly cures Paul's painful bladder infection with just a touch and brings Del's cherished pet mouse, Mr. Jingles, back to life, Paul begins to reconsider the possibility that someone capable of such miraculous acts might not be guilty after all.
As the story progresses, it becomes evident that Percy’s malicious behavior exposes itself through his treatment of Del during his execution, forcing John to endure the trauma alongside him. In retaliation to Percy's barbaric conduct, the officers confine him in a padded cell to reflect upon his transgressions. Under the veil of night, they slip John out of the prison, allowing him to use his gifts to heal Warden Moores’ wife, Melinda, of her brain tumor, thus saving her life. When Percy eventually emerges from confinement, the other officers warn him that any further misconduct will expose him and his many wrongdoings.
As John channels his extraordinary powers, he unwittingly transfers Melinda’s affliction into Percy's psyche, resulting in a surreal series of events that leads to Wharton’s death at the hands of the oblivious warden. In a turning point, John reveals a prophetic vision to Paul, disclosing that Wharton was the true perpetrator behind the heinous crimes, and in that process, gifts Paul with a piece of his supernatural essence. This realization sends Percy spiraling into a catatonic state, ultimately resulting in his institutionalization at the asylum where he had envisioned working after resigning from his position.
A wave of grief washes over Paul as he grapples with the revelations of John's innocence, and he ultimately presents John with a chance at liberation. Despite the sorrow that fills both their hearts, John perceives his impending execution as a merciful act, acknowledging the harshness of existence where suffering appears to be an inescapable constant. In his final moments, John requests one last wish—to watch Top Hat with his fellow officers—before he faces the electric chair.
As he is led to his execution, John is met with the contempt of the parents of the two young girls who still harbor doubts about his guilt. He expresses an irrational fear of darkness, requesting that the hood not be placed over his head. Paul complies with this request, while John's fellow officers—Brutal, Dean, Harry, and others—look on with heavy hearts as Paul carries out his duty, their tears mirroring the deep impact John's story has had on their lives.
In the present, Paul recounts this harrowing tale of John's execution to Elaine, noting that it was the last one he and Brutal witnessed before they chose to leave their positions and devote their lives to the juvenile justice system. He reveals that Mr. Jingles continues to thrive, enjoying an extended life due to John’s remarkable healing powers. Paul also confides in Elaine that he himself has been cursed with an abnormally long lifespan, aging from 44 to 108 years old since that fateful day.
As Elaine departs from this world, Paul grapples with his own mortality, forced to confront the tragedy of outliving those he cherishes as a divine consequence of John’s wrongful execution. At Elaine's funeral, he reflects on the cruel fate that has befallen him, lamenting, > "We each owe a death. There are no exceptions. But, oh, God... sometimes, the Green Mile seems so long."
