High school junior Joe (Nick Robinson), a 15-year-old grappling with the aftermath of his mother's death, resides with his father Frank (Nick Offerman). Their relationship is strained, largely due to what Joe describes as "daddy issues." Joe's older sister Heather (Alison Brie), is engaged to Colin (Eugene Cordero) and has already moved out. One evening, during a family game of Monopoly—an echo of happier times—tensions escalate. Frustrated by his father, Joe storms off and calls the police to report an alleged theft, stemming from his loss in the game.
Determined to break free, Joe ventures out to a party with his friends, where he secretly harbors feelings for Kelly (Erin Moriarty), who is unfortunately taken. A twist of fate leads Joe and the quirky Biaggio (Moisés Arias) to get lost in the woods on their way home. They stumble across a hauntingly beautiful glade, prompting Joe to dream of constructing a house away from home, with the support of his friend Patrick (Gabriel Basso), who also faces parental struggles. Though initially skeptical of Biaggio, Joe feels too shy to ask him to leave, and thus, Biaggio joins the venture.
With Patrick enthusiastically gathering survival books, the trio becomes committed to their project. They sketch blueprints, loot materials from nearby construction sites, and soon sneak away from home to live in their newly built hideout. Their disappearance raises alarm in the neighborhood, but the police deduce that the boys left willingly, bringing only a few necessities.
In the woods, Joe, Biaggio, and Patrick embrace a carefree lifestyle, striving to sustain themselves with fishing and hunting, despite their lack of experience. Joe passionately articulates ideas of masculinity while the boys divide tasks—Joe and Biaggio on hunting, while Patrick typically gathers food. Their ill-fated hunting attempts lead them to a supermarket, where they hatch a plan to buy chickens instead.
As the weeks roll on, their woodland adventure is filled with fun and camaraderie, but Joe begins to miss Kelly. Seizing the moment, he invites her to visit their makeshift home but soon learns that she has broken up with Paul. Much to Joe’s delight, Kelly arrives with friends, and the night turns lively. However, things take a turn when Joe is heartbroken to see her getting closer to Patrick, leading to an emotional crisis.
Tensions rise, culminating in a fight where Joe resorts to sabotaging a Monopoly game with Patrick. After an explosive exchange with Kelly, she storms out, and both Patrick and Biaggio choose to return home, leaving Joe behind. Struggling without funds to buy food, Joe resorts to hunting and catches a rabbit, but with media attention intensifying, Kelly decides to inform Frank of Joe's whereabouts.
In a frantic climax, a snake intrudes into their unkempt home, and in the chaos, a heroic Biaggio rushes to their aid but gets bitten. The scene catapults to a resolution as Kelly and Frank rescue Joe, bringing the snake’s threat to an end. Moments later, an emotional conversation between Joe and Kelly reveals her feelings for him, even as they aren't a couple. Finally, while Joe faces strained relations with Patrick, a subtle moment of reconciliation emerges as they share a laugh, signaling a return to friendship just before the credits roll.
