Shy 14-year-old Duncan goes on summer vacation with his mother, her overbearing boyfriend, and her boyfriend's daughter. Having a rough time fitting in, Duncan finds an unexpected friend in Owen, manager of the Water Wizz water park.
Liam James
as Duncan
Steve Carell
as Trent Ramsey
Toni Collette
as Pam
AnnaSophia Robb
as Susanna Thompson
Sam Rockwell
as Owen
Allison Janney
as Betty Thompson
Maya Rudolph
as Caitlyn
Amanda Peet
as Joan
Rob Corddry
as Kip
Nat Faxon
as Roddy
Jim Rash
as Lewis
Zoe Levin
as Steph
