You've been living the past 15 years in the underground Metro complex in Moscow, following a nuclear showdown between Russia and the USA. The entirety of the world was destroyed and ravaged by radiation into a savage post-apocalyptic wasteland. Only those who took refugee underground survived unchanged. In one of the many tunnels in the Metro, you've been raising your daughter for 10 years, but recently because of a hefty debt with the local mob, you have been forced to rescue her.