A shy and introverted 14-year-old boy, Duncan, struggles with his sense of belonging and self-worth during a summer vacation with his mother, Pam, her condescending boyfriend, Trent, and Trent's daughter. They stay at Trent's beach house where Duncan feels increasingly alienated due to Trent's critical and belittling attitude toward him. Pam, seeking to keep the peace, often sides with Trent, leaving Duncan feeling isolated and unwanted. The summer threatens to be an endless cycle of discomfort and unhappiness for Duncan as he grapples with the complexities of this blended family dynamic and his place within it.

Seeking an escape from the tense atmosphere of the beach house, Duncan discovers an old water park, Water Wizz. There, he meets Owen, the park's carefree and charismatic manager, who takes a liking to the boy. Under Owen’s tutelage and the park's quirky staff, Duncan finds an unexpected place where he feels accepted and valued. The water park becomes a sanctuary for Duncan, offering him both meaningful friendships and a newfound sense of confidence. As he starts to open up, Duncan begins to confront his personal insecurities and the challenges of his evolving family situation.