Michael and Katherine escape the crowd early, retreating to her home. As their intimacy grows, Katherine halts Michael, expressing her need to align her emotional readiness with her physical inclination towards sex. Alone later, she grapples with the intimidating prospect of sexuality.

Michael extends an invitation to Katherine for a ski trip in Vermont with his sister and her husband. Her parents deliberate on the idea of her being away for three nights. As Katherine awaits their decision, she confides in Erica about her anxiety. In turn, Erica reveals Artie's candid admission about questioning his sexuality, and her supportive pledge to aid him in his exploration. The news of parental consent for the trip soon reaches Katherine.

Chapters 8-9

Amidst the snowy landscapes of Vermont, Katherine and Michael find themselves with connecting rooms. As night falls, Michael crosses the threshold into Katherine's room, seeking her company. She urges him to temper his ardor, as she's not ready for sexual intimacy. In this tender moment, Michael professes his love, leaving Katherine hesitant, though she feels similarly. They drift into slumber, intertwined.

Before hitting the slopes the following morning, Sharon, Michael's sister, engages Katherine in a heartfelt conversation. She praises Michael's goodness and sensitivity, expressing a protective concern for him. Sharon's words echo in Katherine's mind, leading her to ponder whether Sharon doubts her sincerity towards Michael.

Michael takes on the role of instructor as he guides Katherine through the exhilarating world of skiing. The pair spends an invigorating day carving through fresh powder on the slopes. As night descends, they retreat to their cozy apartment where they find Ike and Sharon engulfed in a smoky haze of marijuana. Despite having ventured into that realm before, Katherine and Michael politely decline the offer to partake, opting instead to retire to bed. Wrapped in each other's arms, they share an intimate moment, climaxing without the need for full intercourse. Before dreams take over, Katherine whispers her love for Michael.

Chapters 10-13

Upon Katherine's return from the snowy landscape of Vermont, her father voices his concern over her deepening connection with Michael. He expresses his desire for her to remain free from the binds of a single relationship. The following morning, Katherine’s mother attempts to clarify, explaining that her father simply wishes for her to broaden her social circle. During their drive to school, a curious Katherine inquires if her mother was a virgin at marriage. Her mother shares that she was, at least until engagement, whereas Katherine’s father was not. She unravels the different societal expectations of their time—boys experienced more liberty, while girls were expected to preserve their chastity until marriage. Katherine’s mother gently advises her that intimacy can be emotionally binding, yet emphasizes that the choice must be Katherine’s alone.

Later, Erica, ever the inquisitive friend, expresses disbelief that Katherine remains a virgin. Katherine neither confirms nor denies the assumption, preferring to keep her private matters with Michael close to her chest. In confidence, she reveals her deep feelings for him. Erica speculates on Artie’s sexual orientation, suggesting that he isn't gay but perhaps struggling with impotence.

During a double date, Erica bursts with the news of Artie's acceptance to the American Academy of Dramatic Arts—a dream come true. Yet, their joy is tempered by Artie's father's refusal to let him pursue this path. Erica urges Artie to stand up for his dreams, but Michael advises her to let matters be. Katherine later confides in Michael that she has never seen Artie so despondent.

A ski trip beckons Michael away for ten days, providing him the opportunity to earn his instructor's certificate. Meanwhile, Katherine keeps herself occupied but finds herself longing for his return. Her father reiterates his wish for her to socialize beyond Michael, while her mother gently reminds her that she will have to adjust to life without him when college arrives. Spurred by this, Katherine seeks counsel about applying to the University of Vermont, hoping to follow Michael. She anticipates her parents' support but is met with resistance.

Michael, returning unexpectedly from his trip, delights Katherine with a surprise visit. On their date, Katherine makes a light-hearted quip about venereal disease, only for Michael to share a more serious confession—he once had "the clap."

The couple finds themselves at Michael's sister's empty apartment. It is here, amidst the quiet intimacy, that Katherine finally sheds her virginity, though the experience leaves her pondering why it is so heavily emphasized.

In the opening of chapter 13, Katherine receives a call from Tommy Aronson, an old flame now back in town, seeking to reconnect. Perceptive as ever, Katherine realizes his intentions are purely physical and dismisses him without hesitation.

Chapters 14-16

A parcel from Katherine's grandmother arrives, brimming with Planned Parenthood pamphlets. After arranging a meeting with her grandmother, Katherine promptly schedules an appointment with Planned Parenthood. During her visit, a clinician discusses her relationship with Michael and educates her on various contraceptive options. Katherine is also screened for sexually transmitted infections, and by the chapter's end, she selects a birth control pill.

The flu strikes both Michael and Katherine, necessitating a temporary separation. When they reunite for Katherine's birthday, Michael presents her with a necklace, a silver disk engraved with “Katherine” on one side and “Forever … Michael” on the other. Katherine, in turn, reveals her own surprise—she has begun taking the pill.

Finding themselves alone at Michael's house, with his parents away, they seize the moment to express their affection in the privacy of Michael's bed, followed by their inaugural shared shower.

Chapters 17-19

Katherine mentions her sister Jamie's plans to return to a summer camp in New Hampshire, though her own summer plans remain uncertain as her job search yields no results. Michael too is on the hunt for summer employment.

Meanwhile, Erica lands a position at the local newspaper and shares news of her cousin Sybil's secretive pregnancy. Sybil, who skillfully concealed her condition under oversized dresses, plans to place the baby up for adoption.

Denied her parents' consent to chase her dreams of studying alongside Michael at another college, Katherine hatches a scheme with him. Michael decides to pause his academic journey, opting to instruct skiers on the snow-laden slopes of Colorado instead.

Meanwhile, Katherine's father reveals a conversation with Sam Fox, the summer camp director where Jamie will soon be a camper. Sam, in dire need of a tennis counselor due to unforeseen illness, piques her father's interest. Certain that Katherine would relish the opportunity, he assures Sam of her willingness. Yet, the very thought leaves Katherine resistant, as it would sever her closeness to Michael. Her father's insistence leaves her with no other option, and she finds herself engulfed in frustration.

Later, Erica extends an invitation to Katherine, Michael, and Artie, promising a night of celebration at her home, free from parental oversight. They converge to honor Michael's birthday, but the festivities cast a shadow over Artie, who broods over his uncertain future. As the night unfolds, the couples drift to separate rooms. It is within these secluded walls that Katherine reveals her impending summer relocation to New Hampshire. Michael, in turn, shares his commitment to a summer position in North Carolina, a decision swayed by his parents. Together, Katherine and Michael pledge to weather the distance, defying their parents' expectations of a strained relationship.

After the evening draws to a close, Katherine discovers Erica in tears, confiding that she can no longer bear the burden of Artie's struggles. Artie, in a moment of desperation, had locked himself in a bathroom, uttering threats of self-harm. He later emerges from the episode, appearing as if he had been performing a theatrical charade, and absolves Erica of blame.

At the dawn of Chapter 19, Artie has attempted to hang himself from the shower curtain rod, a plan thwarted when the rod gave way. Consequently, he is admitted to a private psychiatric hospital. Both Michael and Erica are left wrestling with guilt for not intervening sooner. The chapter concludes with the trio—Michael, Erica, and Katherine—seeking solace in spirits at a bar, their hearts heavy, their minds blurry.

Chapters 20-26

In the unfolding chapters, Sybil welcomes her baby into the world. Erica and Katherine visit her in the hospital, where Sybil, despite her absence from graduation, resolves to embrace the future by accepting Smith's college offer and striving to regain her health. She also plans to adopt an intrauterine device for birth control. Though she displays a stoic demeanor as she parts with her baby, the moment overwhelms both Erica and Katherine with emotion.

Attending Michael's graduation, Katherine is struck by a poignant sadness when the absent names of Sybil and Artie echo through the ceremony. Her own graduation soon follows, and shortly thereafter, Erica extends an invitation to Katherine and Michael for a retreat at her parents' summer abode on Long Beach Island. Just days later, Katherine finds herself amidst the lush landscapes of a New Hampshire camp alongside her sister, Jamie.

Chapter twenty-two weaves a tapestry of letters, chronicling the exchanged words of longing and life updates between Katherine and Michael. In her correspondence with her parents, Katherine mentions Theo, the head of the tennis program, both in passing and with Erica. A brief, supportive note is also penned to Artie, who remains in the hospital's care.

The narrative of chapter twenty-three paints a vivid picture of camp life through Katherine's eyes. Her burgeoning attraction to Theo becomes evident as she meticulously describes his features. They bond over tennis matches and shared swims. One evening, Theo inquires about the necklace she cherishes, a gift from Michael, inscribed with "Forever." Theo muses on the weight of eternity for someone so youthful. Later, Katherine dreams of intimacy with Theo, awakening with guilt. When Theo suggests a slow dance, Katherine, overwhelmed by emotion, flees to solitude, grappling with feelings she cannot decipher. During a visit from her parents, she unveils a box brimming with Michael's letters, challenging their belief that distance would sever their connection, though her conviction wavers.

Chapter twenty-four delivers the somber news of Katherine's grandfather's passing. Her parents decide against summoning her and Jamie home, respecting her grandfather's wish for a quiet farewell and her grandmother's need for solitude.

Theo offers comfort when Katherine confides her sorrow, gently escorting her back to her cabin with a tender forehead kiss. In a moment of vulnerability, Katherine initiates a deeper embrace, but Theo withdraws, implying a desire not to take advantage of her fragility. Katherine ceases her correspondence with Michael, seeking clarity. Eventually, she drafts a letter, striving for honesty, to confess meeting someone new and her tangled emotions. Yet, the letter remains unfinished, unsent.

Soon, Michael unexpectedly arrives at the camp, only to witness Katherine and Theo in a moment of closeness, hands intertwined. In Michael's motel room, the tension culminates as he seeks intimacy, which Katherine hesitates to reciprocate. Sensing a rival, Michael questions the meaning of "Forever," now seemingly hollow. He concludes their relationship cannot endure unchanged, while Katherine clings to hope. Michael asserts his unwillingness to share her affections. In resignation, Katherine removes the necklace, offering it back, which Michael silently returns to her purse, marking the end of their shared chapter.

Katherine steps through her front door, an unexpected encounter awaiting her. As she wanders the streets with Erica, she inadvertently collides with Michael. He greets them with news: Artie is back at home. Michael then shares a piece of his own uncertain future, revealing that he has been offered a position as a ski instructor in Vail. The prospect of spending winter amidst Colorado's snow-covered peaks looms enticingly, yet doubt lingers—he hesitates, leaving his thoughts unfinished. Katherine seeks to reassure him, her words a testament to an enduring love. With heartfelt promises lingering in the chilly air, they go their separate ways.

In the quiet of her home, Katherine receives a simple message: Theo has called, suggesting another chapter about to unfold.