CoC. Investigating a house in the woods where some children may have disappeared. We broke into the basement through one of those small windows, and activated the generator- from the look of it, there was enough fuel to give the building power until dawn.
We started investigating the house itself, and were alarmed to find that it seemed larger than it seemed possible when looking from the outside. The walls were adorned with paintings of people in chairs- a variety of different people, with no obvious link. A policeman, a woman in an apron, a farmer, some children, a man in a suit etc. The only thing they had in common was they all shared a similar pose in the chair, and they all looked very sad.
In addition, all the rooms were lit with dozens of candles places on mantels, furniture, chairs and tables. They all seemed as though they hadn't been burning for very long, but no light had been evident from outside the house. At any rate, we were glad we had got the lights working anyway.
Then the lightbulbs started to flicker. We stood still in terror for a moment, and then the entire power went. Luckily, the candles were still burning, so we started looking through the rooms. After a while, we realised that we could no longer see through the windows- the outside was just blackness. One of our less stable party members took a candle and walked up to a window, and tried to peer through. He went permanantly insane, with no confirmation about what he saw- except in a note passed to him by the GM.