On October 10, 1941, the Jewish population of the Belarusian village of Krucha was rounded up and shot. This atrocity was not the routine work of the SS but was committed by a regular German army unit acting on its own initiative. Marching into Darkness is a bone-chilling exposé of the ordinary footsoldiers who participated in the Final Solution on a daily basis.

Although scholars have exploded the myth that the Wehrmacht played no significant part in the Holocaust, a concrete picture of its involvement has been lacking. Marching into Darkness reveals in detail how the army willingly fulfilled its role as an agent of murder on a massive scale. Waitman Wade Beorn unearths forced labor, sexual violence, and grave robbing, though a few soldiers refused to participate and even helped Jews. Improvised extermination progressively became methodical, with some army units going so far as to organize "Jew hunts." The Wehrmacht also used the pretense of Jewish anti-partisan warfare as a subterfuge by reporting murdered Jews as partisans. Through military and legal records, survivor testimonies, and eyewitness interviews, Beorn paints a searing portrait of an army's descent into ever more intimate participation in genocide.