The cast is vast, and Koja’s unreliable narration can make tracking allegiances tricky.

How former Nazis were integrated into the Gehlen Organization (the precursor to the BND) and the CIA to fight the Cold War.

At nearly 1,000 pages, the middle section detailing the bureaucratic inner workings of the SS can be slow but is vital for the "factory" metaphor.

To understand the early chapters, it helps to know the history of the German minority in the Baltic states and their "Home to the Reich" ( Heim ins Reich ) relocation in 1939.