Mark Christopher, a successful but weary screenwriter, is struggling to find inspiration for his next script. On Christmas Eve, his friend Virgil, an officer with the Los Angeles Police Department, visits Mark’s apartment with an unusual request. Virgil needs a temporary place to house Susan, a 17-year-old girl who has been arrested for vagrancy and is waiting for a hearing in juvenile court. Despite initial reservations, Mark reluctantly agrees to let Susan stay for the night, believing her story could provide material for his new screenplay.

As the night progresses, Susan's cheerful and unpredictable nature causes both chaos and amusement in Mark's orderly life. She inadvertently helps him overcome his creative block, but as they spend more time together, the dynamics of their relationship evolve in unexpected ways. This development leads to various comical and heartfelt moments that challenge Mark’s views on life and love, upending his perceived notions of what truly matters.