On their honeymoon, Will tells Lake he wishes he’d gone after her that night, but Lake says the time apart was good for both of them and allowed her to spend quality time with her mother. Will expresses gratitude that Julia knew how they both felt, as it led to Lake attending the slam.

The narrative shifts to three months after Will and Lake’s laundry room argument. On the eve of Will’s graduation, he reflects that he’s only spoken to Lake once since their fight, and her indifference to his new job offer convinces him she’s over him. At Club N9NE, where he’s judging, Lake interrupts to perform a poem called “Schooled,” in which she declares she is unequivocally in love with a boy. Will realizes she means him. He changes all the judges’ scores to tens, takes the stage, and performs “Better than third,” confessing he’s decided to put the girl he loves first.

After his performance, Will rushes to Lake and tells her she deserves to come first. They confess their love and kiss. Outside, concerned about being seen together since he’s technically still a teacher, they move to his car for privacy. They make out but repeatedly have to stop themselves from going too far. Will asks her to promise to wait for him if he can’t get out of his teaching contract—four months. She agrees.

They drive home separately while Will calls her and sings Avett Brothers songs over the phone. At home, they kiss in her driveway despite Julia repeatedly flicking the porch light as a warning. Julia finally comes outside to set ground rules. Will declares he’s madly in love with her daughter.

On their honeymoon, Lake jokes they lived happily ever after, but Will notes it lasted only two weeks until Julia walked in on them.

The narrative shifts back in time, two weeks after graduation. Will has successfully exited his teaching contract by enrolling in a master’s program, allowing him to date Lake publicly. On their first public date, they go to dinner and Club N9NE, where Will performs “The Gift,” a poem about how Lake healed him and how his parents would have loved her. Eager to be alone, Will pulls Lake out of the club.

They park down the street to sneak into Will’s house without Julia seeing his car and realizing they are home. In the dark living room, they begin making out on the couch. Julia walks in with a key to retrieve Caulder’s pillow and catches them half-clothed. She breaks down crying, explaining that with her impending death, Lake will soon be forced to raise Kel and become head of household at 18. She wants Lake to stop growing up so fast and enjoy what’s left of her youth. Julia makes them promise to wait one year before having sex, and grounds Lake for two weeks for sneaking around.

When Lake’s grounding ends, Will rushes over. In her bedroom, they kiss on her bed. Will says they need to establish boundaries and a point of retreat for their physical intimacy. They test limits by gradually increasing physical contact until they discover their point of retreat, when they fear they will lose control.

On their honeymoon, Lake asks Will to recount the first time they didn’t call point of retreat—their wedding night, which she remembers as the best night of her life.

On their wedding night, Will carries Lake over the threshold of their hotel room, which he’s adorned with chocolate, flowers, and fruit. She tells him to remove her shirt. He does so slowly, unbuttoning it one button at a time and kissing each newly exposed inch of her stomach. When he asks if she’s sure she’s ready, she says she is completely sure.

After undressing and getting under the covers, Will pulls back to tell Lake something important. He confesses that while he’s had sex before, he’s never made love before—she is his first—and adds that she will also be the last. They tell each other they love one another. He tells her she is the greatest thing that has ever happened to him, and then they have sex for the first time.

On their honeymoon, Lake says she likes Will’s version of their wedding night. They reflect on their journey and how the weekend has deepened their bond. They say goodnight as wife and husband.

On their return from their honeymoon, Will grows sentimental about their shared driveway and house—everything is now theirs. Finding the house empty with a note that the boys are with Eddie and Gavin across the street, Lake suggests they christen the laundry room. Afterward, they walk to what was formerly Lake’s house. They find the boys and their friends, Kiersten, Eddie, and Gavin, having dinner. During their daily ritual of suck and sweet, Kiersten bluntly explains what happens on honeymoons when Kel asks, mortifying the boys. Caulder’s suck is knowing what Will and Lake did on their honeymoon. Kiersten jokes that her sweet is the steady babysitting job she’ll have in a few months when Gavin and Eddie’s baby is born. Gavin announces his sweet: He and Eddie got engaged the previous night. Lake and Kiersten squeal with excitement as Eddie shows off her ring.

Will reflects on all the heartache that led to this moment of collective happiness. When Lake asks about his sweet, he says it is her—always her.

Three years later, Lake is in labor at the hospital. Gavin, panicking about Lake’s pain, has to be escorted out by Eddie. Will feels helpless as Lake refuses pain medicine. Overwhelmed, he steps into the hallway and sinks to the floor, feeling unready for fatherhood.

Kel joins him and presents a star from Julia, who left eight folded paper stars—one for each potential child, four blue and four pink, all numbered. Julia’s note thanks Will for being a father to Kel and for loving Lake, and congratulates him in advance on being the best father any grandchild of hers could have.

Will returns as the doctor announces Lake is ready to push. He nearly faints but pulls himself together to support Lake through delivery. A baby girl is born. A nurse wraps the baby and places her on Lake’s chest. Will climbs into bed beside them. Lake, crying with joy, says their daughter is perfect—she doesn’t care how many fingers or toes she has.

Will picks up the baby’s tiny hand. Her fingers wrap reflexively around his pinky, and he begins crying. He speaks to his daughter for the first time, naming her Julia.

The book concludes with Will’s poem “My Final Piece,” in which he compares life to a puzzle. He describes finding pieces that fit: friends, true loves, dreams, passions, beliefs. He thought his puzzle was complete—edges lined, corners framed, center filled. But when he held his newborn daughter and felt her tiny fingers wrap around his, he realized she was the final, most vital piece. She is the fusion, the glue that binds all his pieces together and completes his life—the element that makes him who he is, who he was, and who he’ll one day be.