We live in an age of miracles when it comes to allegedly unadaptable books actually being adapted. For years, fantasy fans assumed no one could do right by George R.R. Martin's A Song of Ice and Fire books, but then Game of Thrones became a phenomenon for readers and non-readers alike. Diana Gabaldon's Outlander books seemed too larded with historical detail (and the occasional extremely graphic rape scene) to seem plausible as a TV show, but the Starz version has won over most of her audience.

Now comes AMC's Preacher, based on an acclaimed '90s comic book series, by writer Garth Ennis and artist Steve Dillon, whose apparent barriers to adaptation are so numerous and daunting that they make A Song of Ice and Fire look like Bridget Jones' Diary.

The comic is deeply offensive on both spiritual and aesthetic levels — its recurring cast includes both God Himself (rarely up to anything good) and a teenage boy known as Arseface (due to a disfiguring injury that left his face looking like... well...). It mashes up iconic elements from Westerns, Southern Gothic tragedies, and horror fiction of all stripes. It features international action with graphic violence involving weapons ranging from pistols to nuclear missiles, repeated instances of inbreeding and sexual deviance, vampires, saints, angels, demons, ghosts of beloved movie stars, and enough disturbing meat-related imagery to put you off beef forever.

HBO was able to turn A Song of Ice and Fire into Game of Thrones by throwing a tanker ship full of money at all the problems that should have made it logistically impossible. Thrones isn't an exact adaptation of the books — as many Martin fans will gladly explain to you at length — but thanks to all that cash and advances in technology, it captures much more of the source material than anyone might have once expected it to.

With Preacher, the problems go beyond budget and into blasphemy, and tone, and scope. Filmmakers — everyone from Kevin Smith to Oscar winner Sam Mendes — have been trying to adapt the comic practically since it was first published, all of them eventually giving up. Mendes would later confess that he never found the right balance of all the disparate elements, saying, "I couldn’t find a way of defining what it was onscreen." Others couldn't squeeze the sprawling story into a feature film, or find a TV home willing to tell the story at the length, and with the mix of irreverence and utter sincerity, the material seemingly demanded.

Then along came, of all people, Seth Rogen and Evan Goldberg, who have dabbled in genre mash-ups like The Green Hornet and This Is The End, but never tackled anything as ambitious, complicated, and — at least in comic fan circles — beloved as Preacher. And rather than employ the Game of Thrones approach of trying to present the most faithful version possible with the available time and money, Rogen, Goldberg, and Breaking Bad alum Sam Catlin (acting as the hands-on showrunner) have instead come to the sensible conclusion that a straightforward adaptation is madness. Even with unlimited resources and creative freedom, a direct translation would likely be impossible — and the differences between print and TV make it pointless to attempt some of it(*). Yet the raw material at the core of it — the characters, the canvas, the questions Ennis raised about life, the afterlife, and the grand American experiment — is so potent that something great could be fashioned from it, even if it's not what the readers know by heart.

(*) Dillon's art in the comics is frequently disgusting, but in such a stylized way that it's still incredibly readable. Many of those images would just be too hard to watch at length if accurately rendered. Here, for instance, is Arseface in the comics, and Arseface on TV. In both versions, he's meant to be gross but endearing, but the show has to soften the former to make the latter possible.

Their Preacher, which debuts Sunday night at 10, is faithful to the spirit of the comic, but screws around on the letter a fair piece. I imagine the changes will fill some Preacher purists with the same kind of rage the comics' chief villain felt about improper use of inverted commas, but as someone who owns every issue (along with the various spin-off titles), often in multiple formats, I enjoyed the hell out of the first four episodes. The story may deviate wildly at times, there may be new and/or revamped characters, and the show isn't always graceful as it ambles from one tone or genre to the next. But more often than not, it gave me the same giddy sensation I first experienced when a cardboard box filled with Preacher issues arrived from my friend Scott with a note advising, "Read this. You can thank me later. P.S. I'm sorry for much of what you're about to see."

The basics are the same (though the less you know going in, the better, even if the 90-minute pilot may be a head-scratcher for newcomers): Jesse Custer (Dominic Cooper) is the eponymous clergyman, a reformed criminal struggling to do right by his congregation in the dusty, one-horse Texas town of Annville. He has an ex-girlfriend named Tulip (Ruth Negga), whose sweet-as-molasses demeanor conceals a hardcore criminal with skills at violence that border on the paranormal, and a new best friend in drunken Irishman Cassidy (Joseph Gilgun), who's not particularly at home in the blazing sun of Annville. Jesse's a good fighter but a lousy preacher, and on the verge of doing everyone a favor by quitting when a mysterious cosmic force bestows on him an awesome power that makes him much better at his job, but in danger from mysterious strangers who fear exactly who and what he's now become.

Rogen and Goldberg, who also directed the first two episodes (the third comes from Breaking Bad's cinematography maestro Michael Slovis), are essentially slow-playing the comics' opening arc in order to better establish the characters — also including Lucy Griffiths as a single mom who helps Jesse run the church, W. Earl Brown as the Annville sheriff, Anatol Yusef and Tom Brooke as visitors interested in Jesse's new gift, and Ian Colletti as Arseface (Eugene to his friends and family) — and to bend to the demands of TV production. To help flesh out the new material, they've worked in a later storyline from the comics, involving Jackie Earle Haley as local meat and power magnate Odin Quincannon. The story drags a bit, but at the early episodes' dizzying best, they feel like Wes Anderson was mistakenly given a Quentin Tarantino script and decided to film it anyway, standards of taste be damned.

Nearly all the leads have some kind of prior comic book acting experience(**) — Cooper as young Howard Stark on the big and small screen, Negga as an Agents of SHIELD villain, Gilgun in the UK's Misfits, Haley in Watchmen, and even Griffiths in the Constantine pilot — and while this isn't any kind of traditional superhero story, Preacher takes place in a heightened enough reality that their prior work comes in awfully handy. Negga in particular is a delight. The creative team has altered Tulip's backstory, yet Negga plays the role with such joy and confidence that I can almost imagine returning to the comics and feeling the version on the page no longer seems quite right. Haley is being amusingly minimalist and weird, Gilgun has the loose-limbed charm of the best drinking buddy you've ever met (or worst, depending on the night), and if Cooper seems more tentative than his co-stars, it may just be because the series begins with Jesse in a place where he has little confidence in himself or the world around him.

(**) They're also mostly English and Irish, and have varying degrees of success with their accents. On the one hand, Preacher is such a loving ode to Americana that it might seem odd to have so many non-American actors in key roles, or even to have the English Gilgun playing the Irish Cassidy. On the other, Garth Ennis is from Northern Ireland, and the book very much presented a version of America as seen through the eyes of a foreigner who grew up on John Wayne and Clint Eastwood movies, so the added layer of artifice ultimately works.

This is an oddball show, yet even as it's figuring out its proper pace and how seriously the audience should be taking any given scene, individual moments — particularly the chaotic, yet meticulously-choreographed, fight scenes — thrum with such energy that you want to forgive its sins in the same way some of Jesse's parishioners beg him for help feeling closer to the Almighty. Rogen, Goldberg, and Catlin's alternate narrative may ultimately be proven too small to contain Ennis' huge, crazy ideas, but it's not going to be a boring journey on the way to finding that out.

Believe me, I understand the desire to see one's favorite stories come to life on screen in exactly the way they appeared on the page. I sat in a dark Comic-Con theater thrilling to a Watchmen preview clip with Haley that was a near frame-by-frame recreation of a scene from the comic. Then I saw the whole underwhelming Watchmen movie, which retold nearly every major beat of the comic plot, while missing the entire point of the comic itself. (Watchmen the comic is a deconstruction of superheroes; Watchmen the movie an ultra-violent celebration.) And I look at how often the failings of AMC's other comic book adaptation, The Walking Dead, can be pinned on a desire to return to the source material by any stupid means necessary, even if the show at its best long since outgrew its inspiration.

At the January TCA press tour, Rogen told critics that Ennis, having lived through many failed adaptation attempts, had given his blessing to change as much as was necessary for Preacher to function as a TV show.

"We love the comic," Rogen promised, "and we are going to make a show we like. So we hope that that translates to people who love the comic as well. But (our) first and foremost goal is to make a great, entertaining, fun television show that, if you’ve never heard of the comic book, you love."

That's absolutely where their priorities should be, and the early results suggest they're on the right path.

And if it doesn't work, I've still got the original story on my bookshelf, and can thumb straight through to the part where Jesse and the Saint of Killers... well, maybe I'll wait and see if the show gets there first.

Alan Sepinwall may be reached at sepinwall@hitfix.com


NOTE: Preacher will move into the weekly review rotation starting this Sunday night, and my plan is to treat it the same way I have Game of Thrones and Walking Dead in the past: TV show discussion only, rather than constant spoilers from and comparisons to the books. The show is such a huge departure on so many levels that there's frankly not much point in that game, anyway. Maybe down the road, if the stories merge more and I have the time, I might consider a separate post for comic readers, but the goal for now is to treat the show as its own thing.

Alan Sepinwall has been reviewing television since the mid-'90s, first for Tony Soprano's hometown paper, The Star-Ledger, and now for HitFix. His new book, "TV (The Book)" about the 100 greatest shows of all time, is available now. He can be reached at sepinwall@hitfix.com