Balthazar Kovacs, a detective on Budapest's murder squad, is on the trail of a dead man.

Minutes ago, Kovacs received an anonymous SMS showing a body and an address: 26 Republic Square – the former Communist Party headquarters and once the most feared building in the country. But now, amid the ruins of the demolished building, Kovacs finds no dead body, just six members of the Gendarmerie – an elite police force reporting directly to the prime minister – and an invitation to hand over his phone and cease his investigation.

Kovacs has taken his first step on a journey deep into Budapest's dark heart, towards a deadly intersection of the criminal underworld, the corridors of power and the ghosts of history. A journey that will force him to choose between the law and family loyalty.