Czechoslovakia, 1935: Viktor Kosárek, a newly trained psychiatrist who studied under Carl Jung, arrives at the infamous Hrad Orlu Asylum for the Criminally Insane. The facility is located in a medieval mountaintop castle surrounded by forests, on a site that is well known for concealing dark secrets going back many centuries. The asylum houses six inmates - the country's most treacherous killers - known to the terrified public as the Devil's Six. Viktor intends to use a new medical technique to prove that these patients share a common archetype of evil, a phenomenon he calls The Devil Aspect.

1927: Mary Rourke—a Hollywood studio fixer—is called urgently to the palatial home of Norma Carlton, one of the most recognizable stars in American silent film. Norma has been working on the secret film everyone is openly talking about…a terrifying horror picture called The Devil’s Playground that is rumored to have unleashed a curse on everyone involved in the production. Mary finds Norma’s cold, dead body, and she wonders for just a moment if these dark rumors could be true.

After losing his leg to a land mine in Afghanistan, Cormoran Strike is barely scraping by as a private investigator. Strike is down to one client, creditors are calling, and after a breakup with his longtime girlfriend, he’s living in his office. Then John Bristow walks through his door with a shocking story: His sister, the legendary supermodel Lula Landry - known to her friends as the Cuckoo - famously fell to her death a few months earlier.

Victorian Edinburgh. Captain Edward Henry Hyde is chief detective for the City of Edinburgh Police; as such, he is responsible for investigating all murders and serious crimes in the city. Hyde is a striking but severe-looking man who provokes unease, and often fear, in those who encounter him. Nevertheless, Edward Hyde is truly a good man...though he wrestles fiercely with his own unique demons.

Junior Bender is a Los Angeles burglar with a magic touch. Since he first started breaking into houses at age fourteen, he's never once been caught. But now, after twenty-two years building an exemplary career, Junior has been blackmailed by Trey Annunziato, one of the most powerful crime bosses in LA, into acting as a private investigator on the set of Trey's porn venture, which someone keeps sabotaging.