Behind the walls of a forbidden city, the only thing more dangerous than its secrets is the truth.

Deep in Russia, there is an invisible city that houses thousands of men, women and children who live and work behind double barbed-wire fences monitored by armed guards. They are told that they are the creators of the nuclear shield and saviors of the world. They are told that everyone is an enemy. In this hidden world, a mother risks her life to take us inside Russia's largest nuclear city.