That year marked the arrival of John Coffey, a 6 ft 8 in (2.03 m) tall powerfully built black man who had been convicted of raping and murdering two small white girls. During his time on the Mile, John interacted with fellow prisoners Eduard "Del" Delacroix, a Cajun arsonist, rapist, and murderer, and William Wharton ("Billy the Kid" to himself, "Wild Bill" to the guards), a wild-acting and dangerous multiple murderer who was determined to make as much trouble as he could before he was executed. Other inhabitants included Arlen Bitterbuck, a Native American convicted of killing a man in a fight over a pair of boots (also the first character to die in the electric chair); Arthur Flanders, a real estate executive who had killed his father to perpetrate insurance fraud, and whose sentence was eventually commuted to life imprisonment (while serving his sentence, he was killed by another inmate in the laundry room); and Mr. Jingles, a mouse, to whom Del taught various tricks.
Paul and the other guards were irritated throughout the book by Percy Wetmore, a sadistic guard who enjoyed antagonizing the prisoners. The other guards had to be civil to him despite their dislike of him because he was the nephew of the Governor's wife. When Percy was offered a position at the nearby Briar Ridge psychiatric hospital as a secretary, Paul thought they were finally rid of him. However, Percy refused to leave until he was allowed to supervise an execution, so Paul hesitantly allowed him to run Del's. Percy deliberately avoided soaking a sponge in brine that was supposed to be tucked inside the electrode cap to ensure a quick death in the electric chair. When the switch was thrown, the current caused Del to catch fire in the chair and suffer a prolonged, agonizing demise.
Over time, Paul realized that John possessed inexplicable healing abilities, which he used to cure Paul's urinary tract infection and revive Mr. Jingles after Percy stomped on him. Simple-minded and shy, John was very empathic and sensitive to the thoughts and feelings of others around him. One night, the guards drugged Wharton, then put a straitjacket on Percy and locked him in the padded restraint room so that they could smuggle John out of the prison and take him to the home of Warden Hal Moores. Hal's wife Melinda has an inoperable brain tumor, which John cured. When they returned to the Mile, John passed the "disease" from Melinda into Percy, causing him to go mad and shot Wharton to death before falling into a catatonic state from which he never recovered. Percy was committed to Briar Ridge.
Paul's long-simmering suspicions that John was innocent were proven right when he discovered that it had actually been William Wharton who raped and killed the twin sisters and that John had been trying to revive them. Later John told Paul what he had seen when Wharton had grabbed his arm one time, how Wharton had coerced the sisters to be silent by threatening to kill one if the other had made a noise, using their love for each other. Paul was unsure how to help John, but John told him not to worry, as he was ready to die anyway, wanting to escape the cruelty of the world. John's execution was the last one in which Paul participated. He had introduced Mr. Jingles to Elaine just before the mouse died, having lived 64 years past those events, and explained that those healed by John had gained an unnaturally long lifespan. Elaine died shortly after, never learning how Paul's wife had died in his arms immediately after they had suffered a bus accident, and that he then saw John Coffey's ghost watching him from an overpass. Paul seemed to be all alone, then 104 years old, and wondering how much longer he would live.