Harry Powell - 'This is concrete!'

Okay, its a given that a person would get chills up their spine when watching Mitchum chase the kids up a staircase, murder Willa, or creep through Mrs. Cooper's house, but what gives me the creeps is actually, for some reason, right before the chase scene, when Powell tries to look underneath the block to see if the money is really there.

The way he looks up, back at John, with his face illuminated by the light, and says "this is concrete" in a bewildered voice... my God, it just speaks volumes about how he played this character, so larger than life with his evil, and yet so human, at the same time, that a single line like that could creep a person out.