Good Omens, on Amazon (not Netflix) USA / BBC Two (UK)
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This 6-episode series is based on the 1990 novel by Terry Pratchett and Neil Gaiman, the latter of whom is the writer and showrunner for the series. (I've wanted to read the book ever since it was released, but as of the time of this show, I still haven't.) It's a co-production of Amazon and BBC, and since it will air on TV in the UK, I suppose whether you consider it a TV series or a web series rather depends upon where you live. But, since it debuted on Amazon before BBC 2, I'll consider it a web series, regardless. (I'm not sure exactly when it will air in the UK, but I think it's going to be about six months from its US debut, which was May 31, 2019.) I also want to say I wasn't quite sure whether I should categorize it as "fantasy" or "supernatural," but I ultimately decided the latter is a bit more appropriate. But of course, it's also a comedy. (Well, more of a dramedy, really. And definitely quirky; if I had a category for quirky webseries, as I do for TV series, that might well be where I'd put my review. Then again, I could just as well say that if I had all the different TV categories in my web reviews, I'd probably end up filing this under either "miniseries" or "limited series.")
Anyway, the series is narrated by God (Frances McDormand; and her narration rather reminds me Brenda Strong's narration on Desperate Housewives). There is an angel named Aziraphale (Michael Sheen) and a demon named Crowley (David Tennant), who have been friends (sort of) since the beginning of human history. (Incidentally, I want to mention that the "crow" in "Crowley" is pronounced like the bird. I mention this mainly to help avoid confusion with the demon Crowley from Supernatural, whose name is pronounced differently.) Anyway, Crowley was the demon who tempted Eve and Adam to eat the forbidden apple in the Garden of Eden. He and Aziraphale have a conversation about that after it happens, and then apparently they keep in touch throughout the rest of human history, up until it's time for Armageddon. A couple of demons deliver a baby (who will become the Antichrist) to Crowley, who is supposed to deliver him to convent run by Devil-worshiping nuns. This happens 11 years prior to the main part of the series, on a night when a woman named Harriet Dowling is brought to the convent to give birth. (I suppose it's some sort of medical facility as well as a convent. It wasn't really clear to me. But it seems like a safe bet that no outside humans are aware of the nuns' true allegiance, anyway.) She has a video conference with her husband, Thaddeus (Nick Offerman), who can't be with her because of his job as an ambassador. The nuns are supposed to switch the baby Crowley brings with the Dowlings' baby. However, the same night that Harriet arrives, another, totally random couple, Deidre and Arthur Young, also show up to give birth to a son. And the Antichrist accidentally gets switched with their baby instead of the Dowlings' baby. So, right out of the gate, the plan for Armageddon is messed up.
Anyway, the Antichrist is given the name Adam Young, and he ends up living a fairly normal life, for the next eleven years. And he has a few close friends: Pepper, Brian, and Wensleydale. Meanwhile, the Dowlings' son is named Warlock, and Aziraphale and Crowley spend his childhood trying to influence him towards good and evil, respectively. Although actually, both angel and demon want to prevent Armageddon, because they both like human culture, and don't want to see it end. But of course, their superiors have no idea the two of them are friends, and they must at least appear to be doing their jobs properly. The end of the world is supposed to begin when the Antichrist comes into his full powers on his eleventh birthday, at which point a hellhound will appear to him. Aziraphale and Crowley are both surprised when no hellhound comes to Warlock, and they realize they've been working with the wrong kid all this time. The hellhound appears to Adam, of course, and he names it "Dog." (Before he ever saw it, its appearance changed to that of a normal, non-hellish dog.) So... Aziraphale and Crowley will both have to try and figure out who the Antichrist actually is, and find him... to prevent the end of the world, though it's unclear how exactly they'll do that.
Well, that's the first episode, and I don't want to spoil too many details of the other five. But there are several more characters I do need to mention. I guess I'll start by saying Crowley's superior is the Archangel Gabriel (Jon Hamm), and the main two superiors Crowley has to deal with are Hastur and Ligur. We also see the Four Horsemen of the Apocalypse (though actually two of them are women, and they all ride motorcycles instead of horses). There's also a flashback to 1656, in which we see an angry mob led by Witchfinder Major Thou-Shalt-Not-Commit-Adultery Pulsifer. They're on their way to apprehend a witch named Agnes Nutter, to burn her at the stake. Agnes leaves behind a book of prophecies she'd written, "The Nice and Accurate Prophecies of Agnes Nutter," which is inherited by her daughter and son-in-law, Virtue and John Device. They pass it down through the generations, all the way to the present, when it is the duty of Agnes's distant descendant, Anathema Device, to play a part in preventing the end of the world. (She's played by Adria Arjona, whom I had previously seen in the 2017 series Emerald City, though I completely failed to recognize her in this, I'm afraid.) Meanwhile, Witchfinder Major Pulsifer also has a descendant who plays a part in the present story, Newton Pulsifer. Though unlike Anathema, he knows nothing of his ancestor or witchfinders of any kind. Fate will ultimately bring Anathema and Newton together, but I absolutely don't want to spoil anything about how that plays out. However, I do have to mention that before meeting Anathema, Newton meets the last of the witchfinders, Sergeant Shadwell (Michael McKean), who recruits the befuddled Newton as a Witchfinder Private. And I need to say that Shadwell has a neighbor called Madame Tracy (Miranda Richardson), with whom he has a rather complicated... I don't want to say "relationship," though it seems obvious their acquaintanceship will eventually progress in that direction.
The first half of episode three starts in 4004 B.C., and follows various encounters Aziraphale and Crowley have with each other throughout the millennia, before the episode finally catches up to the present. And... things get increasingly bizarre throughout the rest of the series, in large part because Adam's imaginings begin to manifest as reality. But of course there are lots of other things going on, as all the different factions and individuals (some witting, some unwitting) continue to play their parts that lead up to Armageddon (or the lack thereof, depending on how everything plays out, which I'm not going to reveal). I do want to mention that in one episode we hear the voice of Metatron (Derek Jacobi). And in the final episode we briefly see a giant CGI Satan (voiced by Benedict Cumberbatch).
And I don't really know what else to say, because there is just so very much that I don't want to spoil, both about how it all ends, and about the details leading up to the end (and the aftermath). So I'll just say I thought it was a brilliantly imaginative, chaotic, often hilarious, cool, dramatic, and charming series, full of characters I loved. And I really want to read the book someday, because I'm sure it has so much in it that couldn't be included in this series. Anyway... it's been a blast.