Anxious to explore the mysterious hidden world under metropolitan Berlin, an international group of four urban explorers hires a local guide, Kris, who leads them into the maze of escape tunnels and subterranean fortifications under the city. When their guide has a bad fall, two of the girls in the group frantically set off to seek help while Denis, the young American, stays behind. Armin, a former East German border guard suddenly appears from nowhere. Out of sheer desperation, Denis allows Armin to lead them and their unconscious guide to safety and it is at this moment that Denis realizes he has just made the biggest mistake of his life!

Martin Behrens is a Middle East expert for the German intelligence agency BND. He obtains information leading to a U.S. drone strike on a wanted terrorist in Zahiristan. A few days later, there's a terrorist attack on a restaurant – the video claiming responsibility calls it payback for the drone strike. Freelance journalist Aurice, with whom Martin was having an affair, is among the victims – she was investigating corruption at the heart of the BND. Martin soon has to realize that in a world where big corporations profit from arms deals as well as from homeland security contracts, good and evil are sometimes hard to tell apart.