You're stuck inside, unable to leave where you are and growing more frustrated by the day. But it's not quarantine, it's 1910 in the Cascade mountains, and you're stuck in a train that's been snowed in beside a small Washington town that's little more than a speck on the map. And as the snow falls for the sixth day in a row, the steep hillside above you, packed with heavy snow, silently threatens to fall. All it needs is one tiny push for disaster to strike.