What's the most spine-chilling movie scene ?

Not talking about scary, or jump-scare scene, but a scene so disturbing, that leaves you awake at night, and gets you to want to stop watching the movie, but you know you just can't stop watching it. The kind of scene that ilicits a reaction like polystyren scrathing (in my case), or nails scratching on a chalkboard.For me it's the bear scene in Annihilation (with the tunnel rape scene in Irreversible a close second). I still get chills when I hear that desperate 'HELP ME!' in my head when I'm remembering the movie. via /r/movies http://bit.ly/2IxnZ8m