In the opening scene of The Way, Way Back, Trent (Steve Carell) is driving his family to a Massachusetts resort. Because it’s Carell at the wheel of the station wagon, we expect Trent to be a nice but quirky dad. A strong indicator something’s off is the sullen adolescent sitting in the tailgate section.

Duncan (Liam James) isn’t Trent’s kid. He’s the son of his girlfriend, Pam (Toni Collette). The slow bonding process between potential step-dad and step-son grinds to a halt when Trent tells Duncan that on a scale of 1 to 10, he’s a 3, never a great way to begin a relationship. Also onboard is Trent’s daughter Steph (Zoe Levin). When she strips down to a bikini at the shore, she calls the suddenly wide awake Duncan a “perv.” Steph has a coterie of friends at the resort including next door neighbor, Susanna (AnnaSophia Robb), who also crosses Duncan’s field of vision. 

Nat Faxon and Jim Rash, who co-wrote and co-directed, play with audience expectations throughout. As it begins, the focus shifts between the kids and their middle-aged parents. Trent and Pam are both self-centered despite their charade of quality parenting. Duncan starts off as opaque, conceivably somewhere on the high functioning end of the autistic spectrum. He finds his voice and emerges as the main character, while overcoming his “kid brother” status with Susanna.

Trent is an uptight hypocrite with a mean streak. By contrast, Owen (Sam Rockwell), the fast talking manager of the water park, takes a genuine interest in Duncan. Owen has a shady past and a history with Caitlin (Maya Rudolph) his co-manager who’s the one running the show. Rockwell delivers his finely crafted dialogue with credible sarcasm and panache.

Allison Janey as Susanna’s mom steals every scene she’s in. Gorgeous Amanda Peet is Joan, an “older woman” in a bikini top who gives the teenage Lolitas a run for their money.