Fifteenth summer: Fifteen-year-old Chelsea and her family are spending the summer at a cottage on the shore of Lake Michigan where Chelsea meets and falls for Josh--the cute and shy employee at the new bookstore in town. -- Sixteenth summer: Sixteen-year-old Anna falls for Will, a New Yorker visiting her resort island for the summer, but she isn't sure if one summer of love will be worth her heart breaking when he leaves at the end of August.