The fans come out to see the game between the Knights and the Pirates, which will decide who wins the pennant and goes on to the World Series. Though fans are annoyed at Roy for eating himself into a bellyache, they bet on the Knights to win anyway. Most people bet on the Knights, making Roy's sellout to throw the game even more of a betrayal.
Roy feels sick, but he puts up a good front for the other players, who feel better now that he has returned. Max Mercy tries to get a statement from Roy, but Roy rebuffs him. Finally, Pop Fisher comes to talk to Roy. Pop tells Roy that winning the pennant is all he wants, all he hopes for. Pop has come to realize that many people's lives "will go the same way all the time, without them getting what they want, no matter what." Pop asks Roy to go in and "do his damndest." Roy says he will go in, but no more.
The crowd goes nuts for Roy when he comes out—all except for Otto P. Zipp, whose curses Roy ignores. The Knights' star pitcher, Fowler, starts; Roy realizes that Fowler has also been bought by Judge Banner and Gus Sands. In the second inning, Roy goes up against the Pirates' pitcher, Vogelman. Roy holds himself back, letting pitches go by, though Wonderboy is almost "breaking his wrists to get at them." Roy thinks about Memo and about a dream he had in which Memo passed him by in a city and never looked back, never seemed to recognize him.
While Roy stands at the plate, thoughts come unbidden to him, such as the memory of his mother drowning an old tomcat, as well as the trip with Iris when she asked him, "When will you grow up, Roy?" Roy strikes out.
A breeze begins to blow dust over the field; it is drying out. On his next at- bat, Roy gets to first, but the next hitters are tagged out. Roy, now heavy- hearted, considers sending a note to the Judge to tell him the fix is off, but Roy balks when he wonders what he would then tell Memo. He cannot imagine the lonely life without her.
On Roy's next up, Otto P. Zipp begins a vicious run of cursing, and Roy repeatedly send foul shots flying toward the dwarf, finally hitting him in the skull. The ball bounces off Zipp's face and strikes a woman in the face—Iris Lemon, who had been standing up in support of Roy. She tells Roy that she is pregnant with their child, and that he must win this game for the both of them. Roy takes a good, healthy swing, and thunder cracks as he does so, but the ball lands foul—and even worse, Wonderboy has split in two. On the next pitch, Roy, distraught by the loss of Wonderboy, fails to lift the bat.
Still somewhat strengthened by Iris, Roy starts fielding well, deciding against the fix. He tries to persuade Fowler to pitch better, to drop the fix as well. The Knights start doing a little better, and finally Roy is up again, with a chance to win the game. His posture and facial expression at the plate is so ferocious that Vogelman, the Pirates' pitcher, faints dead away. The Pirates send in their relief pitcher, a young, talented man who wants to be a farmer; he is only playing baseball long enough to buy a farm. Roy is prepared to do his best—three good swings—but he strikes out.
Sobbing, Roy buries Wonderboy in the playing field. He goes into the clubhouse and finds his money from the Judge. He takes it and walks up to the Judge's tower, where he finds the Judge, Gus, and Memo counting betting receipts. Roy punches Gus, knocking out his false eye. Roy dumps the Judge's money over his head, snatches the Judge's gun away, and beats him up. Memo tries to shoot Roy, but she misses, and Roy takes the gun away. Memo tells Roy that she has hated him ever since he "murdered Bump." Roy realizes that he "never learned anything from his past life" and now he has to suffer again.
A newspaper headline by Max Mercy reveals Roy's sellout. The article also contains a photo of Roy at nineteen, on the ground and bleeding from the gunshot wound of Harriet Bird. A boy turns to Roy and says, "Say it ain't so," but Roy cannot. He simply weeps.
With much blood and thunder, Roy's big league career comes to its tragic conclusion. Pop's statements about how some people seem to be cursed with a "whammy" is all too relevant to Roy's life. Despite even his own reservations, Roy continues in his single-minded desire for Memo. Unbelievably, when he thinks about life without Memo, he balks because of the "loneliness" that life would bring—completely forgetting about Iris, the woman who actually made him feel good about himself. Unlike the Perceval of myth, who eventually overcomes his youthful stupidity and infatuations, Roy never manages to rise above his own preoccupations with wealth, fame, and Memo—or more symbolically, his greed, fear of death, and oedipal desire for his mother (as critic Earl Wasserman interprets Roy's behavior). Roy's role as the hero-god of vegetative myth, a force of life and rejuvenation, is symbolized by the way the field turns "dusty" and dry while Roy deliberately misses hits. Pop begins to literally decay, scratching his hands and removing his false teeth, as Roy continues to fail.
However, after Roy's discovery that he is a force of life—he has gotten Iris pregnant—he finally understands and accepts his role in the world. There is an immense crack of thunder when he next hits the ball, but unfortunately it is too late. Wonderboy, the almost supernatural source of energy that allows Roy to hit any kind of pitch with ease, breaks under the stress Roy puts on it. In these final moments, the struggle between the realistic tone of the novel and its mythological underpinnings reaches a frantic conclusion. Why does Wonderboy break? In some versions of the Arthur legend, Excalibur breaks when Arthur unfairly uses it against the righteous Sir Lancelot, whom Arthur could not beat in fair combat without the supernatural aid of his sword. But Wonderboy breaks after Roy has decided against the fix—not before. It could be that, by having Wonderboy break, Malamud is abandoning the mythological structure of the novel entirely, leaving Roy to fend for himself in a "realistic" world. If this interpretation is correct, then it makes sense that Roy ultimately fails not because he lacks Wonderboy, but because he goes after a "bad ball," which Pop has repeatedly warned him about. With the end of Wonderboy, Roy has lost his method of channeling his ability as a natural. His crutch gone, he must rely on the same skills that any other good ballplayer must. However, the childish Roy, certain of his talent all his life, has never cultivated these abilities. Left to his own devices, robbed of his status as a mythological hero and a true Knight, Roy succumbs to a bad pitch.
However, there is an alternative interpretation of Wonderboy's destruction and Roy's failure; one that is perhaps not as pessimistic as it might first appear. Roy's failure comes at the hands of a young pitcher—aptly named Youngberry—who may represent the proper course of the vegetative-god cycle. Just as Roy struck out the Whammer at the age of nineteen, Youngberry strikes out Roy. Roy's time has come; he has seen himself as the Whammer before, and now his time has passed. It is notable that, in a broad sense, the novel takes place within a single seasonal year, beginning in early spring with the nineteen-year-old Roy's trip to Chicago, then his early-summer joining of the Knights fifteen years later, through to autumn and then to late autumn, when the trees are dying and the vegetative cycle enters its "death" stage. But the next cycle is preparing to begin, with this new young player striking out ("killing") the old, so that he may take the old player's place the following year. This new symbolic god has dreams of his own—he wants to own a farm, and is only playing baseball to make enough money to buy one. Youngberry offers hope where Roy does not. The young pitcher dreams of "golden wheat fields" and is not interested in setting records or in the game of baseball at all: he is almost unaware of his talent. All Youngberry lacks now, as Roy did, is recognition of his responsibility to the fans—which hopefully will come in time. For Roy, however, it is too late. His time as a cyclical hero-god is over, and he has failed to use the time as best he could. Unlike Perceval, Roy does not achieve the "Holy Grail" of the pennant race. He makes the right decision only when he no longer has the power to act upon it. He even "kills" the fertility goddess when his errant foul hits Iris in the face. But his son is in her womb, and even in the face of defeat, Roy is a force of life.
The ending is again pulled from baseball history. After the famous Black Sox Scandal of 1919—when eight members of the Chicago White Sox sold out to bookies and threw the World Series—a young boy reportedly tugged at "Shoeless Joe" Jackson's sleeve and said, "Say it ain't so, Joe." That infamous line is repeated to Roy, who can find no response but to weep. It is notable that once Roy has come to understand his world, he reaches a new level of invincibility. He defeats the evil forces arrayed against him, although it is, again, too little too late. Roy knocks out Gus's eye, grabs the Judge's gun before the Judge can fire and then brutally beats the old man, and calls Memo a whore. The silver bullet—fired by Memo this time—does not strike Roy now that he has come to understand his life; he knows now that he has learned nothing from his past life, and that he now must suffer again. But in this realization there is hope, for Iris has told Roy that suffering brings happiness. The conclusion of the novel is certainly not as triumphant as the conclusion of the well-known 1984 film adaptation of The Natural, but it is not as downbeat as it might seem. Though Roy is too late to personally save the symbolic Fisher King and the Waste Land, Roy's future is left open. It appears at least possible that he will spend it with Iris and his unborn son, in happiness.