Dohany Street / Adam LeBor.

Budapest, January 2016. The Danube is grey and half-frozen, covered with ice, and the city seems to have gone into hibernation. But not for Detective Balthazar Kovacs. Elad Harrari, a young Israeli historian, has disappeared. There's no sign of violence but something feels very wrong. Elad was working in the archives of the city's Jewish Museum, investigating the fate of the assets of the Hungarian Jews murdered in the Holocaust. It's clear that his research is setting off alarm bells at one of the country's most powerful companies. The more Balthazar digs into the case, the more he is certain that shadowy forces are in play. Someone wants Harrari out of the picture. And the pressure is building: Budapest is preparing for a major diplomatic visit -- if Elad is not found it will be cancelled. The threats against Balthazar soon turn to violence. It's clear that if he is to find the historian he will have to go face-to-face with some very dangerous people -- and confront the darkest era in Hungary's past.