Like the wet drops of something tapping on the ground like a faulty sink, and not just in Anna's apartment where the creature resides.
There's a scene where Anna is staring at a statue of Jesus, and she does nothing else other than grunting.
The sounds of pain Anna releases during her miscarriage.
Even without the whole Cosmic Horror Story aspect, the very premise of divorcing while having to take care of a kid during Cold War paranoia certainly qualifies as Nightmare Fuel.
Andrzej Korzyński's score is guaranteed to keep you on edge, particularly the main theme, aptly titled "The Night the Screaming Stops" on the official soundtrack album.
When Anna runs out of the apartment after being hit by Mark, a truck narrowly avoids hitting her and Mark in the streets, spilling the cars it was carrying. Then there's something terrifying about how calm Anna gets after she dodging the truck and walking away.
During another fight with Mark, Anna cuts herself on the neck with an electric knife and then Mark nonchalantly cuts himself with the same electric knife three times on his arm. With no reaction to the pain.
The private detective Emmanuel coming in contact with the fleshy demon creature hidden in one of the rooms of Anna's apartment. This large blob of a creature just shrouded in darkness. Its eyes staring back at the detective in silence. Then Anna kills the private detective by slashing his face and neck with a broken wine bottle.
Anna suddenly snapping and making odd noises as she beats Zimmerman repeatedly before shooting him with his own gun.
A home video shows Anna teaching a ballet class when she tortures one of her students while staring coldly at the camera. The student takes off crying but Anna remains stern and proud of what she's done.
The ending with Helen looking straight at the camera with her green eyes as the apocalypse happens.
, aptly titled "The Night the Screaming Stops" on the official soundtrack album.