June 1944. When a Wehrmacht war crimes investigator and his escort are killed in an ambush, it looks like an opportunistic act of resistance by the Armia Krajowa, but Jan Kalisz of the Warsaw Kripo has his doubts.

Fortunately, with the Red Army just a few hundred kilometres away, Kalisz's boss, Hauptsturmfhrer Hoth finds his faith in the Fuhrer waning, and lets his Polish detective investigate.

The hunt for the real killers takes Kalisz first to a battered Berlin and then within reach of the Russian guns, but the answer lies with a key witness who's now in a concentration camp. At Auschwitz-Birkenau, Kalisz is reacquainted with his former colleague, Doctor Josef Mengele

By the time Kalisz escapes Mengele's clutches and returns to Warsaw, the city is a powder keg on the brink of exploding. After five years of reluctant collaboration is it finally time for Jan Kalisz to show his true allegiance?