As the curtain descends on their high school journey, longtime friends Andy (Braun), Nora (Deutch), "The Lion" (Arias), and Mike/"Spice" (Broussard) find themselves standing at the edge of summer break, confronted by the stark reality that no invitations had been sent to celebrate their graduation. This group of soon-to-be college freshmen—Andy heading to Dartmouth, Nora embarking on a path to Harvard, "The Lion" set for MIT, and Spice off to Stanford—has reluctantly accepted the prospect of a summer filled with monotonous jobs, their dreams seemingly put on hold.
Andy fills his days teaching tennis while cultivating a connection online with an intriguing Indian pen pal who has captured his heart. Despite the doubts raised by his friends regarding the truth of this virtual relationship, Andy clings to hope that he might meet her, but first, he needs to gather $2,000 to make it a reality. Meanwhile, Nora delves into her ichthyology studies, grappling with her feelings for Erland, an older Australian colleague whose presence lingers in her mind.
"The Lion" finds his footing as a children's MMA instructor, and Spice spends his days working as a kitchenhand, their lives marked by a sense of entrapment. The monotony is broken when "The Lion" receives an invite to an exclusive party at "The Point," a sought-after gated community that promises the escapism they've sorely missed throughout high school. Each friend harbors their ambitions: Andy hopes for some romantic experience, "The Lion" is keen to experiment with drugs, Nora yearns for a boyfriend, and Spice desires a break from his routine.
Amidst the revelry at this decadent party, they quickly rise to popularity, utilizing their unique skills to gain social traction. Spice's culinary talents secure him an invitation to another gathering, while Andy's humorous mouth-catching ability and "The Lion's" tai chi expertise make them both attractive to the partygoers. Even Nora's crush makes an appearance, leading her to flirt and share a few kisses, setting the stage for a hopeful connection. Andy, in a moment of surprising confidence, enjoys a night of passion with one of the attendees, who offers him helpful advice on his initial inexperience—igniting his aspirations for the summer.
As the days of summer amalgamate, Andy finds himself lost in a cycle of deception and temptation while taking on the role of women's tennis instructor at "The Point." It begins innocently when he encounters Gabby, an older woman who suggests a private lesson, invoking a whirlwind of attraction that leads Andy down a slippery slope of infidelity with numerous clients—each unsuspecting of their marital betrayal.
Meanwhile, Nora delicately nurtures her romance with Erland, a situation that stirs jealousy in Andy, who is painfully aware of their significant age gap. Spiraling into hypocrisy, Spice points out Andy's own questionable relationship dynamic with Gabby. The tension escalates until Nora ultimately ends her relationship with Erland, leaving her emotionally reeling.
However, their reckless behavior does not remain unpunished. "The Lion's" escapades with drugs lead to a shocking hallucination during class, which costs him his job. Andy faces a crisis when Gabby's husband unexpectedly returns home during one of their clandestine meetings, forcing him to escape in the nude and drawing police attention. The senior tennis coaches, who share their indiscretions with Gabby, threaten Andy with termination if his own "lessons" don't cease. The breaking point is reached when Gabby's husband discovers one of Andy's sweatbands, ultimately leading to his dismissal.
As summer nears its end, a tipsy Andy mistakenly visits the wrong house, running into Conch, a past classmate who clarifies a crucial detail: he was never truly hated; rather, classmates just opted not to invite him because "nobody is ever invited; they just show up." With this revelation, Conch extends an invite to the impending end-of-summer bash—a chance for redemption.
Reuniting, Andy, Nora, and The Lion appear drained from their respective escapades, while Spice remains blissfully oblivious, suggesting a trip to the farewell gathering to lift spirits. Little does Andy know that a surprise call from Danya (Tasie Lawrence) radically alters his plans; she awaits him at the bus station after emailing him but receiving no reply. With anticipation rising, the trio embarks on a road trip to collect Danya, who immediately expresses her warmth towards Andy upon their meeting. Unfortunately, amidst their joy, Andy is suddenly struck by an urgent need to urinate, followed by discomfort, leading to an urgent diagnosis: a yeast infection necessitating a week of treatment and a strict no-sex policy.
With Andy’s romantic hopes dashed, Danya becomes acutely aware that she may be slipping down his priority list. The tension escalates during the end-of-summer party, where the atmosphere is charged with nostalgia, and Danya can't help but notice the undeniable chemistry simmering between Andy and Nora. Fueled by compassion, The Lion assists Danya with a kiss, only for the moment to be truncated by the arrival of the tennis women’s husbands, suspicious of Andy’s activities.
In the chaos that ensues, Andy openly declares his feelings for Nora, admits to his previously hidden affairs, and even attempts to play the victim due to his yeast infection. His desperate confession earns him a swift reaction—a crushing punch from one of the husbands. Just when the situation seems dire, The Lion leverages his MMA training to safeguard Andy and confront the aggressors.
As partygoers begin to exit, Spice re-emerges, reveling in newfound affection from a girl he impressed with his amateur mixology. The party comes to a head when police officers arrive, yet one recognizes Andy as a helpful figure from the past and, rather than shutting down the celebration, offers the group a ride home, which enhances their social standing among peers. As they bask in their legendary status, the friends share poignant goodbyes, each embarking on their unique paths away from carefree summers and into the gritty realities of college life.
Fast-forward to Andy’s arrival at Dartmouth, where a familiar face from that fateful party greets him unexpectedly. A gummy bear launched with playful aim strikes Andy, providing a delightful moment that kicks off his new journey with a sense of camaraderie as they eagerly anticipate their collegiate adventures together.
