Black Gas

Tyler's brought his girlfriend Soo back to his hometown of Footstep, a footnote of a town located on scenic Smoky Island. The first night they're there, Tyler and Soo go up to his parents' cabin in the middle of the nearby woods for some alone time.

Because they're the only people on the far side of the island, they're thus the only ones on the island who are unaffected when the Bulge, a local inactive volcano, belches out a toxic cloud of gas.

The gas, when inhaled, rapidly suppresses a human's rationality, leaving a crazed cannibal who's constantly weeping black tears. Every impulse is immediately acted upon, and Smoky Island begins to devour itself. Tyler and Soo, neither of whom are in the least prepared for any kind of survival scenario, are forced to fight their way through the town to find a way off of Smoky Island.

Black Gas is a three-issue limited series (January-May, 2006) by Warren Ellis and Max Fiumara, published via Avatar Press. It was followed shortly thereafter by a three-issue sequel, Black Gas 2 (October, 2006-June, 2007).

Despite the similar concept, Black Gas predates Crossed by three years or so, and the similarly afflicted "Droolers" from David Wellington's Plague Zone by a year.

Tropes used in Black Gas include:

Apocalypse How: The gas is initially confined to the tiny island of Footstep. Unfortunately, Footstep is right off the American coastline, and the gas drifts across the water to infect and kill an entire major city.
You Fail Geography Forever: The series takes place at the "northern end of the east coast", according to Tyler, so it should be somewhere in Maine. Despite this, the end of the series shows a nuke blowing a hole in the crust and the "camera" zooms back into space to show enough gas to convert the entire world escaping out of the hole, but instead of Maine or even North America, we see Africa, which doesn't even share a common plate boundary with North America.
Author Appeal: Sort of. Black Gas was written for William Christiansen, the editor-in-chief of Avatar, who's a big zombie fan, so this is sort of like Editor Appeal.

"William has a thing about zombies," said Ellis. "He's been after me for years to write him a zombie book. A ways back, I broke down and devised 'Blackgas,' specifically for him. It's basically me writing a book for my friend to read. Because my friend is sick in the head, it has disgusting violence and gutbusting horror in it. That's the whole deal, really. Sometimes it's just as simple as that."

Badass Normal: Largely averted. Tyler's a media studies major and Soo's an Asian-American history major. They have a couple of good moments between them, but this isn't that kind of story.
Covers Always Lie: One of the alternate covers for #3 has Soo and Tyler surrounded by zombies and calmly blowing them away with handguns. Nothing even close to that scenario appears in the book.
- This is somewhat trumped by the covers for Black Gas 2 #3, most of which feature Soo in sexy, damaged clothing. Soo dies on the last page of Black Gas 2 #2, and her corpse is in #3 for all of one panel.
Deconstruction: In most zombie stories, at least one of the main characters usually has some degree of combat training for one reason or another. One of Ellis's stated plot points in Black Gas is that neither Tyler nor Soo have any idea how to handle themselves in a fight, and it shows.
Downer Ending
Gorn: It's a Warren Ellis book from Avatar, written on spec for the guy who runs Avatar.
Gory Discretion Shot: Averted. There isn't a single one in either volume.
Infant Immortality: Averted. Averted hard.
It Got Worse: Soo makes it off of Footstep alive, but is forced to shoot Tyler shortly after escaping. As she's floating towards the mainland, she realizes that the unnamed city across the water from Footstep was within range of the gas...
- In Black Gas 2, we find out that the title gas works on dogs. Ultimately, The Government, despite knowing that the gas came from a volcanic eruption, attempts to put a end to the whole mess by nuking the city. This cracks the fault line that the gas was trapped in completely the fuck open. The series ends on an Epic Tracking Shot of a cloud of Black Gas covering... Mozambique. Earth is dead.
  - And somehow Ellis still shows more humanity here than Ennis does in the competing Crossed. . .
Made of Plasticine: Every bullet is explosive; every blunt weapon is swung like the hammer of God; anyone who's bitten by another human being has their skin peel off in sheets.
Mr. Exposition: Dr. Menlove. As far as he can tell, the gas gives people the worst case of Tourette's Shitcock Syndrome imaginable - the victim not only loses the ability to suppress unwanted communications, but unwanted actions. He figures this out because he was ~~having a toke~~ stoned out of his fucking mind when the gas hit, and started getting wasted on everything he can get his hands on in order to remain too apathetic to go on a rampage. He's minutes away from OD'ing when Tyler and Soo arrive looking for the keys to his boat, and manages to pass on the information. The rest of the zombies maul him to death before he can die peacefully of the drugs, as if they are pissed off at him for giving away this knowledge.
Our Zombies Are Different: They aren't zombies so much as they're humans gone completely berserk, with a taste for human flesh and a habit of doing every sick, cruel act that's ever occurred to them at any time. The gas causes a rapid series of neurological changes, driving an infected human crazy with hunger, and strips away all civilized impulses. Some people immediately go feral and only attack with their teeth; others still have enough fine motor control to use weapons or drive a car. If a gassed human has eaten enough recently, they may be relatively lucid, but are still completely psychotic.
Pink Mist: It turns out that dropping a large bomb on a hospital full of infected people is a really bad idea. The miasma of vaporized blood and bodies is enough to spread the black gas even further.
Town with a Dark Secret: Smoky Island was the site of one of the "lost colonies," where the original inhabitants apparently all killed one another in some kind of short-lived civil war. Historians have no idea why.
The Virus: The black gas expresses out in a victim's blood, tears, or saliva. If an uninfected person gets those in their mouth, eyes, or an open wound, they'll slowly be overcome. The gas is lighter than air, so being underground at the time of its release or being upwind from the emission site is enough to escape infection, and being under the influence of anything that alters brain chemistry will dramatically slow down the change. An ordinary gas mask will also prevent the gas from affecting a person.
Where the Hell Is Springfield?: Smoky Island is just off the coast of an unnamed northeastern American city. At one point, a rescue operator identifies that he's "dug in at Grenlees," just outside the city's limits, which does not appear to be an identifiable location on the east coast of North America.
Zombie Apocalypse: Well, if Left 4 Dead counts, I suppose this does too.