Lehane adapts the nonfiction book In With the Devil: A Fallen Hero, A Serial Killer, and a Dangerous Bargain for Redemption by James Keene, who is played here by Egerton. A petty criminal, Keene is busted with enough drugs and guns in his possession to get him ten years behind bars, a sentence that likely means he won’t see the final days of his sick father, a former cop known as Big Jim (Liotta ). When a detective named Lauren McCauley (an excellent Sepideh Moafi) comes to him with a proposal, he listens. It’s an incredibly dangerous idea that will take Keene from a minimum-security facility to maximum-security facility for the criminally insane, where he will be surrounded by murderers and career sociopaths. But it will not only lead to Keene’s release but potentially save lives.
McCauley is working with another detective named Brian Miller (Kinnear) on the case of an alleged serial killer named Larry Hall (Paul Walter Hauser). They’ve got him for now, but Hall has a pending appeal that looks like it might be successful, so they need more. Hall has been the suspect in multiple murders across the Midwest, but he’s one of those guys who never tells the same story twice. His twin brother Gary (a phenomenal Jake McLaughlin) and other detectives think that Hall is just a broken storyteller, one of those guys who confesses to things he didn’t do. Miller thinks he’s a true monster who is playing games, and that Hall did commit these horrible rapes and murders. As he investigates recent disappearances that could be Hall’s crimes, Jimmy Keene is moved to a cell near the potential monster, left in an incredibly dangerous situation wherein hardly anybody in the prison knows why he’s there. When he’s not dodging a corrupt guard or navigating the convict power structure, Keene has to slowly get Hall to open up, knowing what he finds inside will be absolutely horrific.
Lehane’s dialogue is sharp from the first scene to the last of the six-episode “Black Bird,” and the entire ensemble comes to life through his words. Egerton finds the perfect balance between grit and vulnerability. He’s just an opportunist criminal, not someone who wants to discuss the rape and murder of children. Egerton captures the emotional stakes of having to listen to a monster in ways that recall Netflix’s excellent “Mindhunter,” which also seems like an influence on the procedural stuff that goes down with McCauley & Miller. Kinnear has a flinty intellectualism that fits the character perfectly, someone who pushes a little harder than the cops who seem to be too willing to believe that Hall is a serial confessor. Hauser is a bit more of a mixed bag. Likely true to the real guy, he plays Hall with a high-pitched affect that can sometimes be like a crutch or even a distraction. He’s better when he’s not leaning into the broadness of Hall’s physicality and vocal tics, particularly in the fifth episode, which is nearly a two-hander between Hauser and Egerton. Finally, there’s the heartbreaking work from Liotta, who was actually ill on set. He imbues his concerned, dying father with a truth that serves as an emotional backdrop for everything that happens on the show.