Days of The Dead

Rating: Mature. For gore, violence, language, and explicit sexual content, and character death.

Pairings: Zutara, Sukka, Taang.

Prologue: Patient Zero

Katara was only sixteen years old when the world ended.

Even now, she can recall the events in perfectly clarity, hear the panicked screams of pain and frantic shouts of the people around her over the rush of her own pulse pounding in her eardrums. Five years to the day, and she can still feel the blood that had sprayed into her eyes as her father put a bullet in the monster that had pinned her to the floor.

She tries not to think about how that monster had been her mother, once upon a time.

x x x

They've coined it the B-Virus, and it spreads like wildfire. By the end of the first month, 30% of the United States population has been infected. By the end of the month, Katara's mother is dead and her home has been burned to the ground.

The military tries evacuation, at first, but it fails when the evacuees start to cannibalize one another. They try quarantine next, and those who manage to escape are cut down or experimented on by the government. The CDC releases the results they get from the testing.

It seems the infected lose all capability for emotion, but they can still feel physical sensation.

It seems they are driven by one desire: the hunger for human flesh.

Katara and her family keep under the radar. Hakoda was a police chief, and the first thing he does is teach her and Sokka how to utilize weaponry.

The first time Katara kills one of the infected, he places a hand on her shoulder and looks at her with something akin to pride in his eyes. She throws up in the bushes, unable to think past the fact that the girl she just shot was wearing a shirt with her favorite band name on it.

Five years later, she still remembers the sunken in face, the missing teeth as the girl's lips widened in an 'O' when Katara put a bullet in her brain.

x x x

Wiping the sweat from her forehead, Katara focused her breathing and looked straight through her crosshairs, fingers gently squeezing the trigger as she waited for her brother to signal her from the other rooftop. Raids aren't usually her thing; the 21 year old medic usually stuck to making deliveries to the lab or helping out in the infirmary, but Suki had broken a pinky and Katara had been the only one willing to take her place.

Their group consisted of only eighteen people, which was hard to stomach when you remembered that they had started out with close to thirty. It was made up of a ragtag group of survivors from their hometown of Alabaster, Michigan. The home base was an abandoned old warehouse near Lake Laogai that housed an underground network of tunnels. Usually, the safe-house was well stocked, but they had been forced into rationing smaller portions and travelling farther and farther away to find supplies.

Which was why Katara and Sokka had been forced to travel deep into the inner city to find food.

Something flashed in her peripheral vision and she turned slightly, her wide blue eyes zeroing in the flash of light that came from her left…and swore as she saw her brother with a pack on his shoulders and running for his dear life. Switching positions and focusing on the undead who were converging into a horde of rotting flesh and diseases, Katara bit her lip and pulled the trigger, picking them off one by one.

Their bodies drop and their insides spill over the concrete when her bullets hit their mark, but the sounds they make are not human; they are far beyond that.

She ignores the guilt that stirs in her belly. By this time, the recoil is a familiar, welcome ache in her shoulders.

x x x

The siblings return to the base successful, Sokka smug at having evaded the horde and coming out clean, without a scratch on him. She stops his ridiculous exaggeration to Suki with a dry comment about how her rifle's magazine was miraculously full at the start of his ridiculous adventure, and empty at the end.

Suki laughs, and Sokka flushes, scowling tightly at her before their father walks into the tunnel they've claimed as a sleeping place. Hakoda waves a hand to silence them from speaking about the raid, and there is a rare smile on his lips.

"There's someone I'd like you all to meet," He states solemnly, the lines on his face lifting, making him seem not so weary, not so tired.

There's something in his tone that tells them not to argue, and the three exchange glances before rising to follow him through the familiar passageways. There are times when Katara feels like a ghost, in these ruins. She hardly ever ventures into the daylight, preferring to stay underground and help the wounded.

Her fingers run softly over the crumbling dirt, and she raises an eyebrow when her father opens the door to the infirmary. Inside, on one of the four cots, there is a old man and a boy.

Blue eyes flicker to the man first; he is old, but there is an air of strength about him that cannot be ignored. Even so, she finds her eyes continually flickering to the boy beside him, entranced by the way he seemed to glow, by the way she could see the blue veins underneath his pale skin.

"Katara," her father starts again. "This is Roku, and Aang."

She waits for him to explain their significance, and ignores the way Sokka and Suki side-eye her, choosing instead to nod at the two males on the cot, curiosity burning in her gaze.

"Aang is patient zero. He's here to seek refuge with us, and Roku is his companion. I think you should show him your work on the serum."

She nods, but focuses on the words that came before. Aang is patient zero. Katara feels something blossoming deep within her chest, something she'd thought died out five years ago: hope.

Aang is patient zero.

She kneels beside him, a smile on her upturned mouth, and takes his hands in her own. She gazes up into his wide, gray eyes, and thinks: you will save us all.

Because Aang -patient zero- is the only one whose blood holds the secret to immunity from the virus that has consumed their world. And that means she can finally, finally complete the antivirus she's been working on for half a decade. She lets the tears spill over her cheeks and smiles through them.

She squeezes his hands when he returns the smile, and knows deep within that something is about to change.

x x x

A/N: Whoo! Zombie AU! Anyway, patient zero is normally the person who STARTED the virus, but Aang is referred to in this way because it also means the first to be immune from it, as well. We'll get a lot more on their backstories next chapter, and one of my favorite characters will make an appearance! Well. Of sorts, anyway. Criticisms and thoughts would be adored! :)