Submarine: Charlotte is an alcoholic trying to complete her first year of sobriety. One evening, when the urge to drink is so strong that she fears a relapse, Charlotte goes to see her sponsor, Jeanne, an alcoholic who has been sober for over five years. However, when Charlotte arrives at Jeanne's, she finds her sponsor in a state of drunkenness. With the roles of helper and cared-for now reversed, Charlotte decides to step in.