Details about The CW's big DC Arrow-verse crossover are starting to come into focus.

The network has tapped Lost and Justified alum Jeremy Davies to play the central villain that assembles the who's-who of superheroes in the three-show crossover.

Davies will take on the role of John Deegan, a doctor at Arkham Asylum for the Criminally Insane in Gotham City, who might just be crazier than the inmates he treats. His machinations will draw Green Arrow (Stephen Amell), The Flash (Grant Gustin) and Supergirl (Melissa Benoist) to Gotham City.

The crossover begins Dec. 9 with The Flash. The three-show event will also introduce Ruby Rose as Batwoman, who patrols the streets of Gotham as a highly trained street fighter primed to snuff out the failing city's criminal resurgence. But don't call her a hero yet — in a city desperate for a savior, Kate must overcome her own demons before embracing the call to be Gotham's symbol of hope.

In addition to Rose, Davies joins a crossover event that will also introduce Elizabeth "Bitsie" Tulloch as iconic character Lois Lane and Cassandra Jean Amell as Mr. Freeze's wife, Nora Fries. Tyler Hoechlin will reprise his role as Superman in the three-night, three-show December event.

Davies' credits include Sleepy Hollow, Twin Peaks, American Gods and Hannibal. He'll next be seen in The House That Jack Built, due in November. He's repped by Zero Gravity Management and attorney Karl Austen.