Set in the Los Angeles of the slight future, the story follows Theodore Twombly, a complex, soulful man who makes his living writing touching, personal letters for other people. Heartbroken after the end of a long relationship, he becomes intrigued with a new, advanced operating system, which promises to be an intuitive entity in its own right, individual to each user. Upon initiating it, he is delighted to meet "Samantha," a bright, female voice, who is insightful, sensitive and surprisingly funny. As her needs and desires grow, in tandem with his own, their friendship deepens into an eventual love for each other.