Let's be grateful Malcolm Bright still sees his childhood psychiatrist.

After the events of Prodigal Son's January 20 episode — which finds the brilliant criminal profiler (Tom Payne) held captive by a serial killer with whom he has some seriously dark history — he's going to have even more to discuss.

"Nobody can do pain like Tom, and this episode pushes him further than he's ever been pushed before," says cocreator Chris Fedak.

But first, a bit of history: In the Fox thriller's premiere, an unraveling Bright was fired from the FBI and began consulting with his mentor, NYPD detective Gil Arroyo (Lou Diamond Phillips), on a case of the week. Since then, he's been investigating a mystery that took root when he was only 10: What memories has he repressed from 1998, when he called the cops on his seemingly loving father, Dr. Martin Whitly (Michael Sheen), a serial killer known as "The Surgeon"? Malcolm does remember seeing a female victim in a trunk; her corpse was never found. What happened on the camping trip he took with his dad after making that discovery? And why did Martin give him a knife?

Malcolm's search for clues about "the girl in the box" put him in the sights of an active serial murderer called "The Junkyard Killer" (guest star Michael Raymond-James). A former protégé of the Surgeon, he actually joined father and son on that fateful camping trip. At the end of the fall finale, he knocked Malcolm unconscious and dragged him off to a secret location. As for what happens next, it's tough to decide which tease is more ominous.

"[The episode] very much speaks to, who is Malcolm in the end? How dangerous is he? Who is the monster?" Fedak says.

Fellow cocreator Sam Sklaver compares the hour to the memorable "panic attack of a scene" in the pilot, when the show set its twisted tone by having a wild-eyed Malcolm chop off a man's hand with an ax to save the terrified stranger’s life: "As soon as we presented that to Fox, they said, 'More! More! More!' And that's what [this episode] is. We just don't let up."

Payne, who imbues Malcolm with gallows humor but also endearing curiosity, innocence, and empathy, describes filming in chains and a costume coated with fake blood for long hours: "Over time, the blood dries and hardens due to the sugar content," he explains. "We would keep it wet during the day, which has its own challenges because it's also very sticky, but when I had to put the clothes back on, they were very stiff. Not the most comfortable!"

That mess aside, Malcolm's kidnapping will do more than scare the bejesus out of viewers who've become invested in his emotional struggle with PTSD. According to the British actor, the experience reveals how protective Malcolm is of his mother, sharp-tongued socialite Jessica Whitly (Bellamy Young), and sister, ambitious TV journalist Ainsley Whitly (Halston Sage).

Malcolm also comes away from the ordeal with some answers, though questions remain that only his father can address. "Malcolm's interactions with Martin are forever changed by what he learns from the Junkyard Killer," Payne says. "If he thought things were bad before, they're now a lot worse."

The back half of the season, which solves the girl-in-the-box mystery, features manipulative Martin much more prominently. That's good news for fans, who have embraced the unpredictable character. Sheen says he often hears things like "My wife loves you! You're her favorite," which he finds quite funny.

Over the past three episodes, Martin has been in solitary at Claremont Psychiatric Hospital, where he's serving a life sentence for 23 murders. (The plot development was convenient for Sheen, who took time off from shooting in New York City last fall to welcome a daughter in his native Wales.) When the show returns, the FBI and NYPD are searching for Malcolm, and Martin is allowed a visitor: Gil.

The cop hasn't seen Martin since arresting him, but intel on the Junkyard Killer is crucial. How does Martin react? "It's pretty extreme," Sheen says. "I know about the relationship he has with my son, and in many ways he has a version of the relationship I would like to have. I'm also aware there's something potentially going on between him and my ex-wife. And he comes and tells me this news." Laughing, the actor adds, "There's a lot going on in those scenes." Especially, he hints, because Martin is never not thinking about how he can use information to his benefit and regain a sense of control.

Moving forward, we'll see more substantial flashbacks to 1998, when Martin was still "in disguise," as Sheen says, balancing his worlds of public respectability and private horror. We'll also be treated to his so-called trial of the century and learn what relationships and bargaining chips he exploited to score his cushy cell and privileges at Claremont. "Being on trial would certainly appeal to Martin's narcissism, and he'd love being the center of attention," Sheen notes. "For his 'work' to finally be appreciated I'm sure would give him satisfaction too."

Again, we're happy Malcolm has a therapist.

Prodigal Son, Mondays, 9/8c, Fox