On his way to start rehearsals at the Théâtre Montmartre, where he has been hired as male lead for a new production, young Bernard Granger tries to talk to an attractive woman, who repeatedly rebuffs him. When he arrives, she turns out to be the costume designer Arlette, a lesbian. He is taken to see the icily beautiful Marion, who is both owner of the theater and leading lady. Her Jewish husband Lucas is believed to have left Paris but is in fact living in the cellars, where Marion visits him each evening to bring books and food and talk about the new production. However Marion is quite struck by Bernard, whom Lucas can just hear through a heating vent but never see. Unknown to anybody at the theater, Bernard is a member of a French Resistance group and delivers the bomb that kills a German admiral.