The novel is told from first person point of view by Paul Edgecombe who was a
corrections officer at Cold Mountain Penitentiary many years ago. The novel starts with
Paul in his old age at a nursing home where he is reminiscing with Elaine Connelly, a
fellow nursing home resident whom he fancies. He is telling her the story of John Coffey
and his time at Cold Mountain Penitentiary death row, nicknamed "The Green Mile" for
the green linoleum floor. He tells her of the year 1935 when John Coffey, a massive
African American man, arrives at Cold Mountain. At the time there are two other
prisoners on the cellblock besides Coffey; Eduard "Del" Delacroix, an arsonist and
murderer whom befriends a mouse named Mr. Jingles, and William "Wild Bill" Wharton,
an uncivil and dangerous multiple murderer who tries to cause as much trouble during his
time on the mile just to spite his conviction.
Paul and the other guards are antagonized throughout the book by Percy Wetmore, a
sadistic guard who enjoys treating the prisoners like animals he can abuse for his own
enjoyment. Despite how much the guards on the mile hate Percy, they have to incur his
presence since he is the governor’s son, which he reminds them quite prevalently. When
he is offered a job at a nearby psychiatric hospital called Briar Ridge. However, Percy
refuses to leave until he is allowed to take on an active role during Eduard Delacroix's
execution. Paul and the guard agree to this. When it comes time for Delacroix’s execution
Percy is responsible for soaking a sponge in brine and placing it under the electrode
placed on Eduard’s head. This ensures a stable current passes through the victim resulting
in a quick and civil execution. Predictably, Percy messes up and fails to soak the sponge
in brine and cause Eduard Delacroix to literally burn to death in a slow and torturous
manner.
Throughout the book Paul repetitively mentions the pain he is enduring due to a urinary
tract infection. This eventually leads Paul to realize that John Coffey possesses
supernatural healing abilities when John grabs Paul by the groin and soon after his
urinary symptoms disappear. These powers not only heal Paul's urinary tract infection,
but they also revive Mr. Jingles after he is stomped on by Percy. These powers lead Paul
to believe that Coffey did not in fact commit the murders for which he was convicted and
also give him an idea to help the warden, Hal Moore. Hal Moore’s wife is dying of a
brain tumor throughout the play. Paul and the rest of the guards devise a plan to break
Coffey out and bring him to the warden’s house to heal his wife and prove he is not an
evil murderer. On the night which the plan is carried out William Wharton is drugged so
he may not bear witness. They put Percy into a straight jacket and he is tossed into the
padded restraint room where misbehaving convicts are usually held captive. They
successfully smuggle John out of Cold Mountain and convince Hal Moore that John can
help. John cures the warden’s wife and presumably incurs her sickness so that she may be
better. When they return to the Mile, John passes the "disease" which he took out of the
warden's wife onto Percy in the form of strange flies that swarm down Percy’s throat and
into his body. This causes him to go mad and fire six bullets into William Wharton
killing him and sending Percy into a catatonic from which he never escapes. Percy is
ironically committed to Briar Ridge.
After this Coffey uses his supernatural powers, taking Paul’s hand, and shows him that it
was Actually William Wharton who committed the murders Coffey was convicted for.
Paul is unsure if he can go through with the execution of John Coffey as he fears his fate
in heaven and does not want to kill one of god’s miracles. He talks to John and asks him
what he wants, but John tells him not to worry, as he is ready to die anyway, wanting to
escape the cruelty of the world. Those healed by John gain an unnatural lifespan. In the
end, Mr. Jingles lives to be taken care of by Paul and dies of old age at Paul's nursing
home, while Paul is now over a hundred years old and wondering how much longer he
will live.