If you dislike Ennis's work, avoid this as you would a plague-infested rapist zombie. (Which isn't a bad way to imagine its content.) You'll want to buy all copies and burn them. Even Garth Ennis fans might think twice, although personally I liked it and bought lots more of the series. Imagine a zombie holocaust, except worse than undead. The Crossed infection will make you want to do every possible bad thing, no matter how revolting or sexually depraved. They use guns. They throw people from planes. If you turned this into a live-action film, it would be unwatchable for 99.99% of viewers. (There's a 2021 Taiwanese horror film called The Sadness that resembles it, apparently, but I'm sure Ennis's version will be more no-holds-barred.)
Also, unusually, this is a creator-owned comic that ran for over a decade under different creators, including Alan Moore. This original mini-series was "arse-shatteringly successful" (to quote Simon Spurrier) and Avatar was keen to do more... but Ennis wasn't interested. To quote him:
"To be honest, there was never really going to be a volume two. William [Christensen, editor-in-chief/publisher of Avatar] would ask me regularly about the possibility, but apart from one or two vague scenes I pretty soon realised I had no more Crossed stories in me. I didn't want to force the issue, either, because I'm very pleased with Crossed and don't want to dilute it with a sequel that I hadn't the ideas to sustain.
"That said, it's pretty obvious that what you have with Crossed is a ready-made fictional world with a good deal of potential for further development, and the Crossed themselves seem to be strong enough villains to maintain an audience. So when William suggested other people doing more I said I wasn't averse to it, so long as: a) I thought the creative teams were up to scratch, and b) my own story and characters would be left alone. Which means no sequel, no more Stan, Cindy, Thomas or Kitrick (or Horsecock, Face or Stump, come to that). Just fresh stories set in the same world."
Ennis ended up returning to the series, as it happens, but only after a while and here and there. It's an anthology franchise, in which each creative team does its own thing and the reader can pick and choose. Occasionally you'll meet a character who's appeared before and Alan Moore created a "100 years later" future world that got continued by Spurrier and others, but that's it.
So, what's it about? Every kind of censorable act, obviously. It was called the sickest comic on the shelves. Beyond that, though?
Underneath the gore and boundary-pushing, this original mini-series is about people. The Crossed are just us. They're doing nothing that real people haven't done, as Ennis has pointed out. The story's following two groups. The survivors are doing what it takes to survive, which is arguably the real horror of Ennis's story. They're still human, but they're in danger of eroding whatever that means and becoming empty shells of themselves. As for the Crossed, there's a group of them too (led by Horsecock) who are capable of self-restraint, scheming and a more slow-burning form of sadism.
The groups are growing in opposite directions, but they'll never cross over. The dividing line is enjoyment of such acts. The Crossed are crazed maniacs who think of nothing else.
I think it's very good, actually. I'd call it an intelligent progression from the zombie genre, which in a print medium couldn't normally equal the visceral reaction of, say, Romero's Living Dead movies. (Trust Ennis to find a way.) Underneath that, though, it's also a surprisingly thoughtful study of its characters in this nightmarish world. Most of them are trying to be good people.
Is it horrible? Yes, in every way it can think of... but subsequent Crossed creators kept trying to one-up each other, so this book now looks almost mild in comparison. (But that's by Crossed standards.)
Would I recommend it? Yes, if you're up for that kind of thing.
"Don't kick the dog."