When a tank truck collides in a tunnel in the ice-cold Norwegian mountains, families, teenagers and tourists on their way home for Christmas are brutally trapped in the darkness. A blizzard is raging outside and the first responders struggle to access the scene of the accident. Time is of the essence, and when the wrecked tanker suddenly catches fire, the situation escalates. In Norwegian tunnels, the self-rescue principle applies: When disaster strikes, it's every man for himself.