AllMovie

Four brave urban explorers descend into the crumbling underground tunnels beneath Berlin, and realize they may never make it out alive after encountering a mysterious stranger in this subterranean nail-biter from director Andy Fetscher. Six stories beneath the streets of Berlin, a complex maze of 25,000 tunnels house untold Nazi secrets. Determined to explore these winding caverns despite the fact that they have been purposely sealed off for the protection of the public, four young adventurers arrive at an inner city club to meet their guide, and explore the remnants of a dark chapter in history. But from the moment the group enters the tunnels, the mood underground turns ominous. In an attempt to discourage neo-Nazis from staking their claim on the city's shame, the German government closed off the tunnels permanently -- or so they thought. Now the deeper the explorers venture, the more lost and confused they become. Just when it begins to seem as if they will never find a way out, however, an outwardly benevolent old man rescues them, and tends to their wounds. Unfortunately for the unsuspecting trailblazers their savior is not who he appears to be, and by the time they realize this, it may already be too late.