First and foremost, the conclusion gives meaning to the title of Kesey's novel. Then, it clears any doubt as to who is the protagonist of this novel. While the indomitable McMurphy is the "free goose" who flies over the cuckoo's nest as in the children's song, acting as agent of rebellion against the stultifying, emasculating forces of sadistic control and technology, it is Chief Bromden who conquers these forces.
Having come from an environment in which his race has been subjugated and their history vilified, the Chief has watched his father destroyed by losing his land and dying of alcoholism. These forces against the Native Americans are perceived by the Chief as the "Combine," likening the routines of the Big Nurse to emasculate and dominate the inmates of the asylum to a huge threshing machine that runs grains through a series of processes until they are ground. He has surrendered to them and allowed his soul to shrivel, his mind and heart to become deaf to the world, existing only within his defeated spirit. As agent, McMurphy becomes the sacrificial victim who dies that the Chief can be reborn from his spiritual death.
McMurphy's influence has also extended to the other men in the ward. Harding challenges Nurse Ratched's assurance that McMurphy will return, telling her she lies.
She tried to get her ward back in shape, but it was difficult with McMurphy's presence still tromping up and down and laughing out loud at the meetings and singing in the latrines....She was losing her patients one after another.
Those who had self-committed leave and return home. Then, after McMurphy is returned to the ward, having had a lobotomy, the men know that his spirit has died. Unable to bear what has been done to one with so much vigor in his heart, the Chief smothers McMurphy. Having heard what has gone on, Scanlon advises him to flee because the Big Nurse will know what has happened; he suggests that the Chief do as McMurphy has shown him. In tune with his native spirit, the Chief sees the moon "straining through the screen," symbolic of his own straining soul as it is reborn. He strains and strains until he finally is able to lift the heavy control panel of the tub-room and hurl it through the panel, screen, and window.
The glass splashed out into the moon, like a bright cold water baptizing the sleeping earth....I ran across the grounds...I caught a ride with a guy...going north and give him such a good story ...he gave me a leather jacket to cover my greens and loaned me ten bucks....
I might go to Canada, but....I'd just like to look over the country around the gorge again, just to bring some of it clear in my mind again.
I been away a long time.
The Chief flees the "Cuckoo's Nest" and reclaims his manhood.