Threshold

High in the mountains, an endless train thunders through a decaying station. This is the Border Post. Your job is simple: blow a whistle to keep the train on schedule. But the air is thin up here. Don’t speak. Don’t run. Don’t look in the train. Just do your job. It’ll all be over soon. It isn’t impossible to breathe in the Border Post. Just impossible to catch your breath. Every exertion is another foot in the grave. Each blow of your whistle is a death sentence. Your only reprieve are air canisters rationed out for your good work. So you better be a good worker.