Set in the spring of 1943, Pastor’s excellent fourth mystery featuring Maj. Martin Bora (after 2014’s Dark Song of Blood) takes the German army counterintelligence officer to Ukraine. In Krasny Yar, a place shunned by the locals, someone has been savagely killing peasants for no apparent reason. Bora has little time to investigate before a higher-profile case claims his attention. Gen. Ghenrikh “Khan” Tibyetsky, a tank corps commander with access to the highest level of Soviet military planning, has offered to defect to the Germans. Khan’s information could be crucial to the battle looming in the Kursk salient. Bora handles Khan’s surrender, but the Gestapo later takes control of the prisoner. When Khan dies in Gestapo custody, an apparent poisoning victim, no one besides Bora, a decent man, seems interested in solving the crime, which may be linked to the murders at Krasny Yar. Pastor effectively melds a well-constructed whodunit with a grim portrayal of the Eastern front.