In post-World War II Vienna, Max, a former SS officer now working as a night porter at a hotel, leads an obscure, shadowed existence, masking his sinister past. His carefully reconstructed life begins to crumble when Lucia, a beautiful and haunted concentration camp survivor, checks into the hotel where he works. Their eyes meet, and an unsettling recognition flickers between them; Lucia was once his prisoner. The two are drawn back into a sadomasochistic relationship that originally blossomed amidst the horrors of the concentration camp. This reencounter stirs the dark memories they had both attempted to bury and reawakens forbidden desires that expose their fractured psyche.

Max's attempt to maintain his anonymity further unravels when members of a secret group of former Nazis become aware of Lucia's sudden presence. These ex-officers are intent on eliminating any loose ends that might threaten the disclosure of their war crimes. As pressures mount and with the grim suspicion looming over their rekindled dark romance, Max and Lucia are compelled to confront their twisted past. They grapple with guilt, shame, and a perverse bond that challenges the remnants of their humanity.