Vienna, 1899. Josef Breuer - celebrated psychoanalyst - is about to encounter his strangest case yet. Found by the lunatic asylum, thin, head shaved, she claims to have no name, no feelings - to be, in fact, not even human. Intrigued, Breuer determines to fathom the roots of her disturbance.

Years later, in Germany, we meet Krysta. Krysta's Papa is busy working in the infirmary with the 'animal people', so little Krysta plays alone, lost in the stories of Hansel and Gretel, the Pied Piper, and more. And when everything changes and the real world around her becomes as frightening as any fairy tale, Krysta finds that her imagination holds powers beyond what she could ever have guessed . . .

As the shadows and echoes between them multiply, it becomes clear that these two narratives are the interwoven threads of one much bigger story, which scours the darkest, most shameful places of twentieth-century history and reveals - in a dizzying final twist - a path back out to the light.