It's the front door.

Oh, Nikola, you were my husband. Curtin, call it on. Look, you're so young and cute. He's asleep in my room. You listen, Marie. You see my warrant. He was laughing when your father found i… Let me guess. He died laughing. And left us to die. Burn it! Monsieur Orlac is now on the platform. Don't you worry. Hold that candle a little higher. I know it wasn't easy for you.