Disclaimer: I own nothing.

Summary: A young soldier finds himself alone, in a world where the laws of death no longer apply.

AN: The survivors will be making an appearance later on. You can't write a Left 4 Dead story without them!

Prologue: Save the Last One

Enlisting after a failed college term and a brief tenure in the workforce hadn't been his first choice, but Michael J. Tisdale wasn't one to think things ahead. He'd always lived by the code, do as little as possible and see what happens. It hadn't really worked out well and after exhausting the kindness of friends and parents and acquiring a substantial bit of debt through student loans, Michael was well on his way to a life of meaningless slacking and dead-end jobs.

Hunkered down in a dark, dank corner in some nameless building's basement saying, "Oh shit, oh shit, oh shit…" Over and over again was hardly where Michael pictured himself at Twenty-four. Disasters usually don't sit down with you and hammer out a schedule that would be convenient for you though, so Mike remained incoherent, his digital-pattern BDU encrusted with dust, grease and blood as he rocked back and forth, fingers clenching tightly to his weapon.

Training had demanded professionalism and while it had lasted all of two seconds for most of the men in his unit, Michael hadn't lost his cool when the so-called rioters had broken down the barricades to the evacuation station his squad had been assigned to protect. He hadn't even lost it when one of the rioters had taken a five-round burst of his M-249, brushed past the concertina wire and sandbags of the hastily-assembled defenses and casually taken a liking to the flesh of his left forearm.

The bite wasn't serious, not really; it didn't even hurt all that much. What got Mike in his current predicament had been the aftereffects of what was more a scratch than a bite. His head had been throbbing painfully by the time the gunfire had died down and despite having been literally in the face of the zombie that had bitten him, Mike hadn't noticed the bite; hadn't felt the warm blood leaking from his forearm as he checked the bodies of the fallen and emptied several rounds into the heads of some of the dead that were still twitching.

Adrenaline was pulsing through Michael's veins as he scanned the battlefield, his throat tightening at the stench of gun smoke, blood and a smell that could only be described as a combination of body odor, urine, shit and burning Twinkies.

"Oh shit man, what is that smell?" Michael managed to bitch between a gag as he glanced at his squad mates. Lieutenant Jonathan Pierce gave a one-finger salute to the private, ordering silence as he brought his M-16A2 to his shoulder, sighting along the devastation that their small unit had made.

A slithering sound was barely discernable over the distant gunfire and moans and Lieutenant Pierce frowned as he checked his left then right before taking a step over the dislodged sandbags marking his cover. A gurgle, followed by a hacking wet cough caused the highest ranking soldier on-site to freeze in place and what happened next seemed to happen in slow motion for Michael.

A tongue, it couldn't be anything else whipped out of nowhere in an impossible display as it latched onto another soldier in their squad. PFC Carlos Esteban made hardly a sound as he was dragged off across the corpses lying on the ground and was dragged by the pulsating tongue over the bodies and across the wire and sandbags of their defenses. By the time the rest of the unit had realized what was happening the PFC was suspended two meters in the air, slowly being raised to the waiting hands of a tall, lanky silhouette leaning over an adjacent rooftop.

The pop-pop-pop of Lieutenant Pierce's M-16 brought Michael back to reality and he took aim of the creature's center of mass, squeezing his trigger in a short, seven-round burst. Die-mother-fucker went silently through Michael's mind as he watched the creature stagger from the 5.56 rounds.

Carlos was freed by the time Michael realized his rounds had not killed the hostile and by the time the PFC had pulled the slimy appendage from his neck and freed his weapon to shout a curse in Spanish to the monster, something else happened. Something much worse.

"What the Fuck is that?" Tisdale had just noticed the shadow moving towards Carlos and had managed to voice his question when the walking corpse took hold of the second-generation Bolivian soldier and began feasting on the recovering soldier's arm.

The corpse was not much more than a walking skeleton. The entire of the creature's abdomen was missing and what looked to be intestines trailed behind the zombie. The creature's chest had been ripped up just as badly as the midsection and Michael couldn't have pegged it for a man or woman if his life depended on it.

Screaming in agony, Carlos fought off the walking corpse, managing to free his wounded limb before the creature's teeth descended on his other, gnawing off the soldier's fingers. Michael about lost his lunch when he saw parts of Carlos drop out of the undead creature's rib cage and by the time he'd leveled his weapon, Lt. Pierce took ten long strides across the distance separating him from Carlos, un-holstered his M-9 Beretta sidearm and put a round through the feasting corpse's temple in a point-blank execution.

The corpse dropped from Carlos and Pierce dragged the swearing and slightly incoherent soldier back into the building they were guarding while the rest of the squad took extra care to watch the rooftops for more rioters.

It had taken less than three hours for Carlos to turn and he'd taken Pierce with him. By the time the screams of civilians had warned the soldiers standing guard outside the safe-house it was too late for most.

Unloading in a room full of American citizens with a SAW was hardly a fantasy of Michael's, but it had saved his life and he hadn't been the only one shooting either. When the smoke cleared and a good ninety percent of the civvies were corpses that wouldn't come back, the broadcast came in to separate and neutralize bitten individuals be they civilian or military. No exceptions.

Corporal Robert Jenkins had started shouting at someone at that point and Michael had looked over to see his friend of two years and fellow soldier put two rounds into the chest of a bitten old man, then the little girl the man had been shielding.

Both had been bitten and it didn't occur to anyone that there was an immunity. Everyone knew what happened when a zombie bit you and Bobbie put two rounds in each of the dead civvies' heads before the situation sank in to everyone present. Chaos erupted again in the small safe house and gunfire took down infected and uninfected alike.

By the time the shooting stopped, Michael pulled his left hand from his weapon's barrel, cursing at the burn on his fingers from the heat generated by the sustained fire. Pulling an olive-colored bandanna from his cargo pocket, Michael noticed the stares from his squad mates. Following their gazes, Michael's eyes widened as he saw the exposed bite he'd received hours before.

The certainty of death offers no comfort to a man, and in that moment, when the knowledge that he was going to be put down like a rabid dog entered Michael Tisdale's mind he did the only human thing; he panicked.

Gunfire, the sound of breaking glass and the concussive boom of an M-67 grenade were all that filled the next several seconds, but somehow Michael had managed to get outside of the building unscathed. The entrance of a small group of undead attracted by the screaming of the civilians and the scent of fresh kills had contributed greatly to Mike's survival, but the ability to run with reckless abandon while maintaining the coherence to use short controlled bursts had saved Mike's life.

Twenty minutes of running blind through a dying city and ignoring the pleas of the few living he came across had found Michael in a relatively abandoned warehouse. A few of the undead dressed in uniforms depicting the shipping company that owned the warehouse staggered about, but Michael managed to sneak through the infected without a sound, his combat boots drowned out by the sounds of gunfire, screams and screeching tires.

A small stairwell and an equally small storehouse in the warehouse's basement had provided Michael the safe haven needed and the soldier clutched to his weapon, sweat soaking his clothing as he panted in the darkness, rocking back and forth as he tried to ignore the murders his squad had just committed and the faces of the men he'd trained and fought with before they were obliterated by his grenade or buried under the mangled bodies of the undead.