While on route to the cirque of unclimbables in the Northwest Territories we had stopped at a base camp for the night. After the rest of my group had gone to sleep for the night I stayed up to clean the dishes. Sitting in the absolute silence on Canada's north I heard the strangest and most violent noise I can ever recall.

It was far enough away that I wasn't worried about anything but still, the hairs on my neck stand up just thinking about it. I still have no clue what it was. The closest thing I can think of is that noise that zebras make, mixed with pissed off cats, and somebody screaming in pain. All of these noises combined, extremely loud for about 20 seconds, then back to silence.