William comes to Copenhagen, the city of his father's birth and makes friends with Effy, a fourteen year-old girl who is half his age and works in a hotel. They set off on an adventure to uncover his family's sordid past and William finds Effy is the only one who understands him and falls for her even their age gap. For William to accept his past, the mature beyond her age Effy must learn to be a kid again, and William, a man whose growth was stunted with his father's abandonment as a child, must learn to finally grow up.