After her husband is gunned down in the line of duty by a drunk driver, Rose Lovejoy is haunted by violent nightmares and overwhelming grief. Unmoored and unpredictable, she roams the city streets at night, reciting passages from the DMV driver handbook while confronting reckless drivers face-to-face. But when she is aggressively tailgated one night, her fragile grip on reality shatters—and the unthinkable happens.