Roamer: Greetings to all. Frankly I am surprised that no one has done a crossover between these two yet, considering the similarities. This is my personal project, which means it will not be interfering with The Prototype Shinobi's progress, as that is Plague's work. I only help her out occasionally. This crossover is set at the start of the Infection in Left 4 Dead (as we do not have L4D2 yet...) and approximately 4 months after Prototype. Like TPS, Alex is the main focus of the story, though I will consider if he will team up properly with the Survivors later or not. Also, while I especially love the concept behind the Charger and Jockey in L4D2, for continuity reasons I have no choice but to exclude them. Just thought it would be wise to mention that now.

Disclaimer: I do not own Left 4 Dead (god company of FPS games that is known as Valve) or Prototype (Radical Entertainment).

Roamer: Hope you enjoy it. Note that this story in general is rated M for gore (due to Infection ass-kicking by the Prototype) and language (I hate ratings).

7:30 AM - Fairfield, Philadelphia

Alex Mercer was silent in his seat at a street café, sipping a cup of coffee while watching the bustling streets, the pedestrians going about their business, the cars with their drivers honking at the ones before them. Even though he had escaped Manhattan a long time ago, the calmness of Fairfield was still quite the contrast compared to what had happened in those three weeks.

Four months ago, after dealing with the Supreme Hunter, Alex managed to sneak out after the military quarantine was lifted, and currently was enjoying a (relatively) normal life in the city of Fairfield, Philadelphia. He managed to settle in rather comfortably and managed to get a job at the local university as a lecturer. This would not have been possible without the help of his sister, Dana, who had managed to recover quite well after the incident. It was a simple matter of omitting certain...facts, tweaking information of his workplace. Soon he was a scientist for a medical company in Manhattan before deciding to resign and moving to Fairfield. That actually wasn't really far from the truth, as GENTEK WAS a pharmaceutical company publicly, and the nature of its...experiments would have fallen under the medical category if you stripped away most of the gory and disgusting parts of it.

Alex sighed to himself, quickly shaking those thoughts out of his head before calming down with another sip of his coffee. It wasn't worth it to think back to the incident. It was in the past. Besides, it wasn't like another outbreak like that would happen any time soon.

In a dark room lighted only by the multiple screens that were displaying different things, a person was snoring in a chair. The person's sleep was unfortunately interrupted as a glaring red alarm light suddenly lit up, as loud sirens rang, shattering the previous silence. Wiping the sleep out of his/her eyes, the person turned towards one of the screens eye-level to him/her while pressing a few buttons.

"Goddamnit what frigging happened this ti-"

The person stilled in his/her actions, staring incredulously at the information that scrolled down the screen he/she was looking at.

"...Who the FRIGGING HELL decided to activate a LEVEL NINE-THOUSAND-AND-ONE MURPHY'S LAW SITUATION?! THAT'S A FRIGGING BITCH IN PAPERWORK DAMNIT!!!"

Alex soon finished his coffee, before standing up and, leaving the cash and a tip on the table, walked off towards the university he was currently employed. After four months since the incident, Alex reigned in his destructive tendencies and made extra sure not to push past people in the large crowds with his enhanced strength. After 15 minutes, he finally got to the university, where the students were starting to head for their morning lectures. He just happened to pass the dorms when he looked up, happening to see one particular window had its curtains drawn and, if one looked closely, had a miniature zombie model on the window sill.

Alex smirked to himself, his path temporarily diverted towards the door to that particular dorm room, whose resident, Zoey Masters, happened to be an interesting eighteen-year-old. Apparently, from what the other professors had said, Masters had holed up in her room for the first semester (which had ended a month ago) watching B-rated zombie movies and other old horror movies. This had, of course, affected her grades badly, so she was threatened with either getting them up, or getting dropped out. Naturally she had decided to buck up, but occasionally reverted to her old habits. Apparently last night was one such case, as the curtains would not normally be drawn that tightly.

Alex walked up to the door, before rapping on it loudly with his knuckles. There was a short crash, as if someone had fell off a seat (or a couch in front of the TV for Masters' case, Alex inwardly chuckled), after which a few soft curses could be heard, before a quick "Coming!" was heard. Soon the door creaked open a crack, as Zoey Masters' face became visible through the space. Her face quickly displayed shock as it registered in her mind just who happened to be at the door, before taking on a sheepish look as she opened the door wider.

"Um...Hi Mister Mercer, sir..."

"Please Miss Masters, I've told you before, you can just call me Alex, or at least don't add the sir."

Zoey's face simply blushed while looking even more sheepish as Alex looked over her shoulder, observing the mess in her dorm room.

"Errr...I can explain this sir."

"No need...*sigh* Miss Masters, while I understand that those movies have a sort of appeal to you, you should focus more on your education, or else you'll be disappointing your family greatly. Besides, you can just watch those movies again after you've gotten your grades up, and the other professors wouldn't mind...well, at least until the next time your grades start to suffer again of course, then you're in hot water...again."

Zoey smiled at that, the earlier tension eased at Alex's attempt at humor, when she had an 'Oh snap' look on her face, before dashing back into the dorm room while slamming the door behind her, before the sounds of items being chucked about could be heard. Alex chuckled to himself before turning around and continued on his way towards the university building. Apparently Zoey had just remembered that she was late.

Roamer: I do hope that you all enjoyed the prologue. While I did mention that I will need to consider whether Alex should properly team up with the Survivors, I did not mention anything previously about familiarity between any of them beforehand.

EDIT: I have only just caught wind that there will be a DLC for L4D2 where the Survivors of both games meet up. It will open up the possibility of transferring this story gradually into L4D2. However, I will wait for more information of the DLC's content before making plans for L4D2. I want my Leeroy Jen- I mean Charger.