They have a love-hate relationship with summer. Sidney and Asher should have clicked. Two star swimmers forced to spend their summers on a lake together sounds like the perfect match. But it's the same every year—in between cookouts and boat rides and family-imposed bonfires, Sidney and Asher spend the dog days of summer finding the ultimate ways to prank each other. And now, after their senior year, they're determined to make it the most epic summer yet. But their plans are thrown in sudden jeopardy when their feud causes their families to be kicked out of their beloved lake houses. Once in their new accommodations, Sidney expects the prank war 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. Their truce should make things simpler, but six years of tormenting one another isn't so easy to ignore. Kind of like the undeniable attraction growing between them.