You pick your way through the woods, which are growing dimmer all the time. Little by little, the sound of water ahead of you gets louder. You know what else gets louder? The sound of something crashing through the trees behind you. That sound is getting louder even faster than the sound of running water, so you'd better pick up the pace!

Finally! There it is - a river. You vaguely remember crossing a bridge before you got lost, so the road where you parked your car must be on the other side of the river. It's moving pretty fast though. It doesn't look very safe to cross here, but whatever that thing is, it's getting closer and closer. Are you a good swimmer?