Craig and Austin develop a quick friendship that becomes a turning point in Craig's life. Austin is charismatic and invites Craig into his friend group, but Craig's behavior, including a violent incident during a friendly boxing match, causes tension and alienation from Austin's other friends. Craig's intense need for connection and validation leads to increasingly uncomfortable and dark situations between them.

Tami, Craig's wife and a cancer survivor, initially appears distant and disconnected from Craig, hinting at reconnecting with an ex-boyfriend. Craig's self-absorption causes strain, especially when he forces Tami to relive his sewer exploration experience, resulting in her getting lost for days. Eventually, Tami leaves Craig after finding sexual satisfaction on her own, though the film implies a possible later reconciliation before Craig's final breakdown.

Steven, Craig and Tami's son, has a smaller role but serves as a calm and confident contrast to his father Craig's increasingly unstable and self-absorbed behavior.

The film immerses viewers in Craig's miserable existence, using subjective filmmaking to depict his fantasies of being a heroic figure in Austin's life. Craig's intense desire to feel valued and essential leads to an inability to accept rejection or boundaries, culminating in his emotional detonation and social alienation.

Craig's attempts to integrate with Austin's friend group initially go well but deteriorate after a boxing match where Craig's aggressive behavior makes the group uncomfortable. The friends quickly grow to dislike Craig, which exacerbates his feelings of rejection and isolation, contributing to the film's dark and unsettling tone.