" There is a sweet little horror story that is only two sentences long:
'The last man on Earth sat along in a room. There was a knock at the door…'
Two sentences and an ellipsis of three dots. The horror, of course, isn't in the story at all; it's in the ellipsis, the implication: what knocked at the door. Faced with the unknown, the human mind supplies something vaguely horrible. "

― Fredric Brown , Space On My Hands