It's 1983 and eleven-year old Cat Rossi watches the launch ramp at her father's marina where dozens of trucks patiently wait to back their boats into the shallow water. They're out-of-towners, Paychecks, her brother likes to call them because they bring the money. But just for the summer.

Cat's used to the carousel of part-time friends until she meets Will Henderson, the only son of a wealthy doctor. They bond over ice cream and pinky promises, and when August ends, Will vows he'll be back. Cat's not counting on it; things change, people do too, but when Will eventually returns to the marina, they quickly fall back into their easy friendship. Every year, Cat waits for Will to return to the marina for the summer, and every year their connection is tested as they wade the awkward waters of adolescence into adulthood.