Who is Gavriil Ahrenski?

Gavriil Ahrenski is a Russian officer who finds himself as a Prisoner of War placed into Auschwitz camp. He is a born survivor, having survived the partisan life, the cbear cage and Auschwitz itself. We see him being questioned after the war by the NKVD. His adversary is Victor Beria a young officer who is establishing a case against his friend Andrey Vlasov who formed the rebel Russian Liberation Army who sided with the Germans and then turned their weapons in Prague.