I was originally going to comment that “Through My Most Grievous Fault” has been The Exorcist‘s least religious episode to date. I’m not saying that in a bad way–as I’ve said before, religion in pop culture can be a very difficult balancing act with wide chasms of pandering or erroneous portrayals on either side of a very narrow tightrope. To date, The Exorcist has portrayed the Catholic worldview correctly without really coming off as evangelical.

“Through My Most Grievous Fault” initially leans towards the risk of pandering this episode, with the effort to get the Salesman (Robert Emmett Lunney) out of Casey (Hannah Kasulka) coming off as a rather routine, predictable effort. We’ve got an old priest (Ben Daniels) and a young priest (Alfonso Herrera) taking on the devil, so a couple of Hail Marys and some holy water while a symbolically on-the-nose storm rages outside, and we’re good, right?

Except we’re totally not. I’m giving credit to The Exorcist for fooling me thus far–given the limited future solicitations for this show, I’d wagered that Geena Davis was on a limited contract and the Rance family’s saga would be wrapped up this week, and then we’d be into some weekly procedural show with a Daniels-Herrerra buddy cop drama. “Through My Most Grievous Fault” proves me wrong with a major bombshell that that shows that this story still has a long way to play out. It also expands the franchise’s mythology while still keeping things quite within the realm of religion.

So let’s get back to religion for a moment. Catholic-Christianity posits, at its most basic level, that God created everything, but that an ancient moral incident occurred between God and man which leaves them divided and man broken. An earlier and worse version of this break occurred when a number of God’s first creations, the angels, made a similar break and were eternally cast from paradise. These angels (now called “demons”) can’t be forgiven–they knew full what they did and accepted the consequences. Man, at least, has a limited sense of his sins, so there’s still an opportunity to correct course and reconcile with God.

As Marcus points out this episode, the demons hate that God is trying to reconcile with man. During part of the exorcism, Marcus calls the Salesman an angry child, throwing a temper tantrum. He’s not wrong. During the battle within Casey’s soul, she desperately asks the Salesman why he’s doing this. “Do you know what it is to have paradise within your reach?” he asks. “Never be allowed to touch it? Imagine never sleeping again, or eating, or having the sun on your face.” That’s pretty much it. That’s the Salesman in a nutshell. He’s an ancient entity who’s out of God’s graces forever, and if he can’t do it, nobody else can either.

So, because man is broken, demons like the Salesman want to do nothing more than exploit those breaks, and oh man, does he do it. He very adeptly finds the weak points of each of our main characters and tears the chasm wide open. Father Tomas is, unfortunately, very easy to exploit–he’s weak in both the groin and the heart, and after the Salesman tempts him with an image of Jessica, he goes running off to the real thing. (Priests are supposed to be celibate, let alone not committing adultery.) With Casey’s sister Kat (Brianne Howey), he hits her in the brain, tempting her skepticism of religion and her love of her sister. This inspires her to take a very stupid action which, from her limited point of view, seems entirely sensible. And with Marcus, the Salesman tempts his pride, making him feel like a failure as both a priest and a human being as he dredges up painful memories of who his parents were.

(Before I move on, I do have to credit Hanna Kasulka’s acting range in this episode. How cool is it that she has to play both a frightened possessed girl and Robert Emmett Lunney in her own body? Despite Lunney’s voiceover, she convincingly plays the part of two people through her mannerisms and facial changes.)

The Salesman makes one critical error here, whether he realizes it or not…but he’s a demon, so pride is his own weakness. The Salesman attempts to ruin both Angela (Geena Davis) and Henry (Alan Ruck) by revealing that Angela’s been keeping secrets. Angela’s got a secret past, and it’s a huge revelation that changes everything we know about the show and brings it much deeper into the storyline of the original story. We won’t spoil it here, though be warned that Exorcist fans are probably already talking about it. Let’s just say that you should watch the episode before going onto any forums.

Because here’s the thing–in the Christian worldview, sin likes to hide, and if it’s hidden, it remains untreated and the sinner never gets better. In the Garden of Eden, the first thing Adam and Eve did upon sinning was to hide. In this case, Angela’s been exposed, but her first impulse is to seek out Tomas and confess who she really is and what her past actions mean for her family. Sin and darkness can’t stand “the light,” and in forcing Angela to confess what she’s been hiding, the Salesman may have just handed Tomas and Marcus the key to defeating him.

We’ll see how this plays out. The Exorcist sadly goes on a break just before Halloween, but we’ll be back with it on November 4.

Rating: Four and a half Bibles out of five.