In the pilot of “Evil,” a forensic psychologist and lapsed Catholic named Kristen (Katja Herbers) lies in bed, frozen in terror, her eyes open wide, as a demon—black and shrivelled, with bright-green eyes and long claws—taunts her. He ducks under her nightgown and says, “Hey, you got a scar down here. What is that, a Cesarean?” He skitters into a corner of her bedroom and urinates as she looks on, humiliated and paralyzed.

The next night, however, Kristen foils the demon, who has introduced himself as George. She tapes a sign on the ceiling above her bed, and, after George slices off one of her fingers, she stares up. “I can’t read it!” she says in relief—he’s only a night terror, since, she explains, Wernicke’s area, the part of the brain that interprets language, is dormant during sleep. “Well, if I don’t exist, then this won’t hurt,” George says, raising his knife and stabbing her in the heart, as she wakes up gasping.

That’s the pattern on “Evil,” at least in the first few episodes. Every supernatural event has a practical explanation—but, then, every practical explanation has a sinister shadow as well, the suggestion that something very bad is going on, something that rationalists can’t quite escape. Maybe religious people are delusional, seeking meaning where none exists. Or maybe the pragmatic ones are the real naïfs. Possibly both things are true, which is how the Devil builds power, in a world that feels designed to magnify malevolence, online and off, by blurring our ability to tell what’s real from what’s imaginary.

“Evil” is the latest series by Michelle and Robert King, the married showrunner team who created a triptych of complex, innovative series for CBS: the Obama-era drama “The Good Wife,” about a corporate lawyer married to a scandal-ridden politician; the experimental zombies-in-Washington satire “BrainDead,” which burned through its single nutty, politically prescient season in 2016; and “The Good Fight,” the spinoff of “The Good Wife,” a smart and savage (and, often, surreal) response to the Trump era. That last show is now entering its fourth season on the streaming service CBS All Access, a platform so poorly designed and badly marketed that it might as well be demonic, at least for anyone who wants her favorite show to become part of the political conversation.

“Evil” marks the Kings’ return to Original Famous Ray’s CBS, a network that people can watch for free—one of the remaining “big three” that used to be television. It’s a more straightforward sort of show than “The Good Fight,” but that’s interesting in itself. In a time when the critical conversation is dominated by cable and streaming, HBO and Amazon, the Kings are a fascinating rarity: normcore auteurs, diplomats on the publicity circuit, whose specialty is bending network formulas to subversive purposes. Earlier this year, word of an internal struggle leaked out. The Kings had planned to air an animated musical sequence on “The Good Fight,” about how readily the media self-censors in order to reach the Chinese market, only to have CBS demand that they cut it. The Kings threatened to quit. Then they insisted that CBS run a placard, reading “CBS HAS CENSORED THIS CONTENT,” in place of the sequence. In the end, the couple settled on a softer approach: the placard went up, but for eight and a half seconds, not ninety. As a result, many viewers perceived the situation not as a protest of real censorship but as a meta-joke. It was an ironic demonstration of a theme that recurs on the Kings’ shows: the appeal of pragmatism, and also its pitfalls. Sometimes the road to Hell is paved with compromise.

Like the two “Good Wife” shows, “Evil” is built on a familiar TV structure, the case-a-week procedural. It’s a buddy-detective series about a skeptic and a believer, in the venerable tradition of “The X-Files,” with a little (and sometimes a lot) of “The Exorcist” tossed in. In the pilot, Kristen, a frazzled mother of four, weighed down by student debt, her mountain-climber husband somewhat mysteriously abroad, takes a part-time gig with a priest-in-training, David (Mike Colter, who played Lemond Bishop on “The Good Wife”), who investigates possible demonic possessions. Kristen checks the subjects for mental illness; a third partner, Ben, played by Aasif Mandvi, is an I.T. expert/engineer/science guy, who figures out if the trouble is neither demons nor psychosis but, say, copper poisoning. Each week, the team investigates a new case, but there’s a broader arc building, too, involving a sinister figure played by Michael Emerson, a rival psychologist intent on overturning cases in which Kristen testified in her former job as a prosecutor’s expert witness. He may also be a colleague of her night visitor, George.

There’s a bit of expositional throat-clearing, early on—and Emerson’s threatening-nerd act can feel a little on the nose. (The Kings have always had a weakness for manifesto-shouting bad guys, like Michael Sheen’s Roy Cohn-esque bully, on “The Good Fight.”) But there’s a seeping air of dread, right away, along with solid scares, oddball laugh lines, and smart character work. A clever plot about a tyrannical theatre producer destabilized by a demonic Amazon Alexa-like device delivers, down to its disturbing final shot. Another, about a psychotic nine-year-old, is more predictable—especially for fans of “Law & Order: S.V.U.”—but it, too, has an ending that lingers. The refusal to come down on one side or the other could begin to feel like a bait and switch, but for now it’s a flexible metaphor, allowing space for multiple forms of the uncanny.

The cast is universally strong, especially Herbers, who, with her warm eyes and her air of wary dishevelment, makes Kristen feel strange and a little dirty, as if she were burying enormous, chaotic emotions. She’s particularly good in scenes with her four daughters, who keep tumbling onto the sofa with her, chatting and giggling, with an organic family sweetness. This makes it all the more frightening when her kids are in danger, which they are pretty much all the time, whether they’re being lured into a virtual-reality game or just wandering around their ramshackle house. A Halloween episode, with a scary little girl in a mask, nearly gave me a stroke.

The show lacks the mythic grandeur of ambitious horror movies such as “Us” and “Midsommar,” but, despite its humbler aesthetic and its basic (in both senses) pleasures, it, too, feels soaked in modern anxieties, full of coded politics, with a special interest in the difficulty of distinguishing madness from amorality. Robert King is a practicing Catholic and Michelle King is a secular Jew; in interviews, they’ve said that the show grew out of debates about the sources of evil, which they see as being on the rise. The rationalist heroine, Kristen, has little in common with Diane, the glam litigator of “The Good Fight,” but both women are unsettled by a sense that their value system—the idea that, through careful questioning, truth might emerge—is unmatched with the moment. There’s no mention of Trump; this isn’t a show that CBS needs to censor. Yet it’s very much about how lies warp the world—and how tempting it is to adopt the liars’ methods. When, in one plot, Kristen uses a “deepfake” recording on the stand, she can justify her behavior: the rival psychologist really did say those things; she’s just re-creating them. But the moral line is fudged, the norm eroded.