1961. Hidden deep within central Soviet Russia is a place that doesn’t appear on any map: a city called Arzamas-16. Here a community of dedicated scientists and technicians is building the most powerful nuclear device the world will ever see – three thousand times more powerful than Hiroshima.
But days before the bomb is to be tested, a young physicist is found dead. His body contains enough radioactive poison to kill thousands. The Arzamas authorities believe it is suicide – they want the corpse disposed of, the incident filed and forgotten. But Moscow is alarmed by what’s going on in this strange, isolated place.