The film is based on the French play "The Human Voice" ("La Voix humaine", 1930) by Jean Cocteau, in which a desperate woman tries to avoid being left by her lover by a series of phone calls. In the film, TV actress Pepa Marcos is depressed because her boyfriend Iván has left her. They are voice actors who dub foreign films, notably "Johnny Guitar" with Joan Crawford and Sterling Hayden. Ivan's sweet-talking voice is the same one he uses in his work. About to leave on a trip, he has asked Pepa to pack his things in a suitcase he will pick up later.