Nick lives with Amy, pretending nothing is wrong, while he finishes his manuscript. He titles it Psycho Bitch, and when it’s finished at last, he goes to Amy with “weak legs” to show her the manuscript and walk out forever. Amy looks at the book, tells Nick he has “perfect timing,” and declares she has something of her own to show him—it is a pregnancy test, and it is positive. Nick, in disbelief, makes Amy take another test, in front of him. Still unbelieving, he takes her to the doctor’s office for a blood test—the doctor confirms that Amy is truly pregnant. Nick realizes that the clinic never destroyed his semen sample, and Amy has used it to impregnate herself.
Amy has one-upped Nick once and for all. Though he thought the threat of his manuscript would be enough to mute Amy, he has forgotten that his wife does know him better than anyone. By dangling the promise of fatherhood—and a chance at redeeming his own father’s mistakes—over Nick’s head, she places him in her clutches for good.
Amy tells Nick that she needs him to do some things “for [her] security.” She demands he destroy his manuscript, and sign an affidavit that it was he who bought the stuff in the woodshed and hid it there, and that though he once thought Amy had framed him, everything is now “good” between them. Nick asks what will happen if he refuses—Amy replies sweetly that “that would be awful.” Nick realizes that in the battle for control over their marriage and story, he has been “thoroughly, finally outplayed.” Nick is Amy’s prisoner—with his child in her womb, she has him “forever.” Nick deletes his manuscript willingly, unable to bear the thought of losing his child.
Nick is willing to submit to whatever Amy asks of him now that a baby is on the way. Flynn is making a larger comment, through this swift and decisive end to Nick and Amy’s silent war, about the ways in which being in a marriage can either strengthen or destabilize someone. Married couples know each other better than anyone—and this means they know each other’s weaknesses profoundly.
Nick calls Boney to tell her the news—she tells him to take care of himself. Nick heads to Go’s to tell her as well. He expects her to be at least a little excited, but instead she is furious, and accuses Nick of being “addicted” to Amy. Go predicts that Nick and Amy won’t make it eighteen years—one of them will kill the other. Nick, though, says he finally has a chance to be “the best husband and father in the world.” Go collapses on the floor and cries.
Go and Boney react in horror and muted solemnity, respectively, as they come to realize that Nick is firmly and forever under Amy’s thumb. Go wants a different fate for her brother, but it is too late—Nick and Amy have chosen one another and all that comes along with the twisted partnership they’ve created.
In spite of the madness of the situation, Nick feels he is “finally a match for Amy.” He can feel her changing him—he was a boy, then a “man, good and bad,” and is now, at last, the hero. Amy is his “forever antagonist,” and their story is “one long frightening climax.”