Duncan (Liam James) isn't having the best time spending the Summer with mother Pam (Toni Collette), her boyfriend, Trent (Steve Carell), and Trent's daughter, Steph (Zoe Levin). So he gets a job at a nearby water park to find some time away from his family. There, he meets park manager Owen (Sam Rockwell), who becomes a father figure to the awkward teen.