June 1944. When a Wehrmacht war crimes investigator and his escort are killed in an ambush, it looks like an opportunistic act of revenge by the Polish Resistance. But Jan Kalisz of the Warsaw Kripo, investigator and Polish double-agent, has his doubts.

Fortunately, with the Red Army only a few hundred kilometres from the city, Kalisz’s boss, Hauptsturmführer Hoth, finds his faith in the Führer waning, and allows an investigation.

The hunt for the real killers takes Kalisz first to a war-torn Berlin and then within reach of Soviet artillery, but to uncover the truth he must enter the very gates of Hell. And waiting for him at Auschwitz-Birkenau is his former associate, Doctor Josef Mengele, the Angel of Death…

Warsaw is a powder keg on the brink of exploding. After five years walking the knife edge between deception and collaboration, is it finally time for Jan Kalisz to reveal his true allegiance?

The explosive finale to the acclaimed Warsaw Quartet series.

'One of the most impressive recent historical crime series... The quartet is a tour de force, brilliantly researched and vividly portrayed... The very very best of historical fiction' Paul Burke, Crime Time FM

'Powerful and gripping... Jackson brings the series to a close with remarkable force. The novel combines a compelling murder mystery with fast-paced action and relentless suspense, all grounded in meticulous historical detail. The atmosphere is richly drawn, capturing both the desperation of occupied Poland and the bitter fighting of the Warsaw Uprising. Particularly striking are the scenes set in Auschwitz, which are deeply unsettling and linger long after reading. Overall, this is a great conclusion to the Warsaw Quartet. It offers not only a gripping story but also a vivid exploration of a complex and often underrepresented chapter of the Second World War, ensuring it resonates as both a thriller and a powerful piece of historical fiction' Alan Bardos for Aspects of Crime

'A compelling, evocative story of evil stalking amidst the chaos of war' Giles Kristian

'A dark, twisting thriller ... Jan Kalisz, Douglas Jackson's police officer hero, is the natural heir to the late Philip Kerr's Bernie Gunther' Andrew Taylor

'A remarkable crime debut What raises the novel to another level is in the atmospheric evocation of a city in the process of being systematically obliterated by the Germans and brought to life again by Jackson's pen Gripping stuff, a series that could develop into something impressive and a goldmine for Philip Kerr Bernie Gunther fans' Maxim Jakubowski, Crime Time

'Immensely powerful and vivid .... This is historical crime fiction at its best' Chris Lloyd

'The writing is scalpel-sharp, the unrelenting savagery of the Nazi occupation vividly painted With this book, Jackson will rightfully be regarded as one of the UK's finest crime writers' Ben Kane

'A taut, tense thriller Gutsy and gripping, this is perfect for fans of Chris Lloyd and Robert Harris' D. V. Bishop
'Jackson has created a brilliant mash-up of WW2 thriller and a serial killer chiller, and in so doing brings a fresh perspective to both. Sharp, intelligent writing that makes for a compelling read' Alison Belsham

'Jan Kalisz is a dazzling addition to the canon of compromised heroes... A thrilling wartime adventure story' Russ Thomas

'Jackson brings the tension, brutality and paranoia of Warsaw of the period into murderous life. A knife-edge thriller' Douglas Skelton

'A dark story set against dark times, you practically need a torch to read it' Alec Marsh, author of Rule Britannia
'Jackson has written an utterly compelling novel ... A remarkable piece of work, a fine piece of craftsmanship' Scotsman