Prague, 1935: Viktor Kosárek, a psychiatrist newly trained by Carl Jung, arrives at the infamous Hrad Orlů Asylum for the Criminally Insane. Located in a medieval mountaintop castle outside the city, the facility houses the country’s six most treacherous killers. Viktor hopes to use a new medical technique to prove that these patients share a common archetype of evil, a phenomenon known as the Devil Aspect. But as he begins to learn the stunning secrets of these five men and one woman, Viktor must face the disturbing possibility that they may share another dark truth. Meanwhile, in Prague, fear grips the city as a phantom serial killer emerges in the dark alleys.