Ben Thomas is about to celebrate his eighteenth birthday with his friends at his grandfather's lakeside estate. His best friend, Jack Foster, has invited Megan Dills, a relatively new student at Franklin High, to the birthday party and surprises Ben by telling him just before the party begins. Little does Ben know that the adventure of a lifetime is about to begin. After the party ends, Ben and Megan are thrown into a dilemma together through no fault of their own.