A French man recalls his moviegoing adventures at a now defunct titular theater as a journalist for the film magazine Cahiers du Cinéma during the mid-1950s.

Judith, a 40-ish year old hospital clown who lives alone, is increasingly unsettled by Francis, her next-door neighbour, a joyful and invasive retired military. Her suspicions are heightened when disturbing details are discovered about him, leading her to spy everything he does. Lost between paranoia and reality, Judith becomes consumed by her obsession. What is eventually uncovered is far more horrifying than she ever imagined...