Monstrumfuhrer by Edward M. Erdelac

In 1936 Dr. Josef Mengele discovers Victor Frankenstein's lab journal in the attic of an Ingolstadt dormitory and is tasked by the Reich Institute with replicating his reanimation procedure.

While hiding in a bookstore in Warsaw, a pair of Jewish twin brothers, Jotham and Eli Podczaski, come across the letters of Captain Walton to his sister, detailing the ill-fated story of Frankenstein.

When Jotham and Eli are captured by the Gestapo and encounter Mengele in the gray confines of Auschwitz KZ, they alone recognize the origin of his bizarre, sadistic experiments. Jotham hatches a plan to escape the camp and travel north, to find the only being capable of stopping Mengele from providing the Third Reich with a new race of undying stormtroopers; the only being on earth who will believe them ... Frankenstein's original creature.

"Ed Erdelac once again proves a master of historical fiction, as well as seamlessly blending literature into reality." --The Horror Fiction Review