1961. Hidden deep within the forests of central Soviet Russia is a place that doesn’t appear on any map: a city called Arzamas-16. Here a community of dedicated scientists, technicians and engineers are building the most powerful nuclear device the world will ever see – three thousand times more powerful than Hiroshima.

But ten 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 and the incident forgotten. But someone in Moscow is alarmed by what’s going on in this strange, isolated place.

And so Major Alexander Vasin – a mostly good KGB officer – is despatched to Arzamas to investigate. What he finds there is unlike anything he’s experienced before. His wits will be tested against some of the most brilliant minds in the Soviet Union – eccentrics, patriots and dissidents who, because their work is considered to be of such vital national importance, have been granted the freedom to think and act, live and love as they wish. In Arzamas, nothing can be allowed to get in the way of the project. Not even murder . . .

Intricately researched, cunningly plotted and brilliantly told, Black Sun is a fast-paced and timely thriller set at the height – and in the heart – of Soviet power.