In the alternative world of Wolf by Wolf, the values of the Third Reich reign supreme in the world. These values place a heavy emphasis on appearance. Yael and her family are singled out for extermination because they are Jews. In the mind of Hitler, Jewish physique and coloring is a degeneration of the Aryan ideal. When Yael is first subjected to Geyer’s experiments, her purpose is to shed her Jewish appearance and mimic the blond hair and blue eyes that are so prized by the Reich. Geyer suggests that some members of the ruling elite might want to acquire these traits themselves. Although their bloodlines might be pure, they don’t fit the physical ideal.

Because appearance means everything to the Nazi regime, looking a certain way carries survival value. Dark-skinned foreigners and people with obviously Semitic features are immediately suspect while the Aryan ideal goes unchallenged. If a person can look a certain way in the Nazi world, that appearance offers freedom, economic advantage, and even life itself. Once Yael learns how to control her shapeshifting abilities, she realizes she can exploit this trait to her advantage. It allows her to avoid certain death on a number of occasions.