At the end of her Junior year of high school, unpopular Mallory Flynn finds herself dating none other than "the" Devon Masters, captain of the soccer team, and things honestly couldn't be better. But when summer vacation rolls around and her newly acquired boyfriend rolls out to spend the summer with his family, Mallory is left to once again spend her summer with Lucien, her best friend since she could walk.

When Lucien brings along another girl to what had always been exclusively /their/ thing, the ugly green monster rears its twisted head and suddenly Mallory's picture-perfect "best-friend" relationship with Lucien isn't so perfect anymore. Plagued for weeks with confusing feelings of jealousy, Mallory finds herself questioning a lifetime of friendship. Confrontation is inescapable, but with it comes a revelation that has Mallory unsure of everything she believed as truth up to this point in her life.

Left for the first time to sort things out on her own, Mallory has to dig into the deepest, most honest parts of herself to find the truth. But what she wants to know most when the inevitable truth is revealed is whether or not Lucien will be there to help pick up the pieces of herself and put things to rights, or if her summer will end with the bittersweet taste of unrequited feelings burning harshly on her tongue...