The film unfolds within the hallowed halls of high school, where 16-year-old Monroe "Mo" Harris (Griffin Gluck) finds himself in a precarious situation when he is unexpectedly summoned by the principal and a police officer. Their serious demeanor signals the turmoil that is about to ensue, setting the stage for a narrative that delves into the intricate dynamics of relationships rather than assigning blame.
At the heart of Mo's tumultuous journey is Zeke Presanti, portrayed by Pete Davidson. This enigmatic 23-year-old captivates Mo with compelling stories of freedom and rebellion. Their bond, rooted in shared experiences with Kate (Emily Arlook), Mo's older sister and Zeke's ex-girlfriend, creates a unique mentor-student dynamic. Although Kate has moved on with her life, Mo still idolizes Zeke, gaining access to a lifestyle filled with older peers. Unfortunately, Zeke finds himself stagnating in a part-time job, lacking ambition.
As Mo attempts to navigate the challenges posed by his parents, Reuben (Jon Cryer) and Sherri (Julia M. Murney), and Zeke's influence, he is inevitably drawn into an intoxicating world of excess and partying. Zeke introduces him to the realm of drinking, leading to chaotic repercussions—Mo wakes up to a pulsating hangover, desperately attempting to function in school while grappling with the aftermath of his reckless choices.
This newfound notoriety catches the eye of Stacey (Thomas Barbusca), who seeks Mo's help in procuring alcohol for a senior party. With Zeke's assistance, Mo manages to supply the needed goods, enhancing his reputation further amongst peers but leaving him feeling out of place. At the same gathering, he finds himself enchanted by Sophia (Oona Laurence), a classmate whose transformation into the iconic Hermione Granger sparks an effortless connection between them.
Conversations with Zeke and Holly (Sydney Sweeney) about Sophia reveal differing viewpoints on how best to approach her. Holly encourages Mo to be authentic, while Zeke suggests that Mo should distance himself from her. All the while, Zeke wrestles with his own issues, entangled in secret dealings with Kate, now in a relationship with Doug (Esteban Benito), culminating in Zeke's increasingly immature behavior during their visits.
As Mo continues to navigate the party scene, he finds himself faced with new requests from Stacey and navigating the complications that arise from his interactions with Sophia. When Mo attempts to reject Sophia's advances, it leaves her feeling disheartened. Simultaneously, Zeke's downward spiral progresses, culminating in Holly's breakup with him, propelling Zeke into solitude while Mo leans on Holly for comfort, resulting in a moment of romantic connection.
The dramatic tension escalates when Stacey loses control of his vehicle after a night of partying, leading to dire consequences. With the police investigating the abandoned car, Mo finds himself in a precarious position as he struggles to maintain connections. A dramatic climax unfolds during a chaotic street party, where Zeke witnesses the fallout of Mo's recent escapades, with Mo cleverly evading the authorities.
As their night concludes, a heartfelt conversation occurs between Mo and Zeke, with Mo expressing his feelings of alienation. The fallout from Mo's decisions culminates in a confrontation at home with Reuben regarding Mo's drug use and behavior, resulting in grounding and loss of privileges.
In the aftermath, Mo shifts to a new school, where a surprising encounter with an old face—Isaac—opens the door for new possibilities. Their reconnection leaves Mo with a sense of cautious optimism as he takes tentative steps toward reclaiming his social life and future.
