Eighteen-year-olds Sidney and Asher have spent every summer together, since they were twelve. Every summer it's the same-in between cookouts and boat rides and family-imposed bonfires, the two spend the dog days of summer finding the ultimate ways to prank each other.

Now, the summer after their senior year, the two know that the end of their forced family vacations is nearing an end, and each is determined to make this last summer the most epic yet. But when the two families are kicked out of their beloved beach houses just one week into their eight-week vacation, their last summer is suddenly in jeopardy.

When the two find themselves in uncomfortable new accommodations, Sidney expects summer to continue as usual. But then she gets a note-Meet me at midnight. And Asher has a proposition for her: join forces for one last summer of epic pranks, against a shared enemy-the woman who kicked them out of their beloved vacation homes. But can these two put their pasts aside and actually work as a team? And with their attention finally on something other than tormenting one another-can they ignore the obvious attraction building between them?