[A/N: Prototype wikia has so, so much speculation, lol. Great fic base.

For gu_tango, who helped out a lot with plot details that I had totally forgotten about and was very patient with my constant annoying questions (like "how did Cross contact Alex again?" and lots and lots of other questions about Cross) and who bombarded me with Cross x Alex doujin over the last few days. Thanks. : )]

Monster's Playground

Chapter 1

I

Humanity was a virus far more insidious than what it was; two days and five hours from achieving his revenge, and the living virus codenamed Blacklight still pervasively thought of itself as a he, still breathed, hurt, hated and cared, thought of itself intrinsically as Alex Mercer. Alex had been the first body he had copied, instinctively, and just as instinctively, he felt a deep-seated unease at using any other shape.

Two days five hours and fifteen minutes from his revenge, and Alex decided, perched on a rusted billboard over a building scarred four days back from a wayward strike package, that he was tired.

Alex Mercer the human had intentionally released a virus that he had known would murder millions, in one of the most crowded cities in the world. Alex Mercer the virus had tried – and succeeded – in suppressing the outbreak. Old habits, perhaps, or residual guilt; Alex still wasn't quite sure. The memories of scores of the consumed provided no clarity on what it meant to be human. Below, chaos yet reigned on the streets; outside of the slowly expanding military zones, the lawless districts were rife with murders, lootings and rapes as humans fought over dwindling supplies.

Disgusted, Alex leaped out into space, willing himself forward, landing with a crunch and claws dug into concrete, running over the rooftop and leaping back into space. This semblance of flight was the sole, exhilarating joy that Alex took in his current existence, the air that roared past and dragged at his clothes, high enough up above the ground, above the stench of rot and living decay.

Central Park was quiet. Difficult to defend with bulky vehicles and subject to potential attack from all sides, the military had temporarily abandoned the park to the remaining infected, which haunted the lawns, hissing and occasionally fighting amongst themselves.

Alex skirted the park, on alert. Dana was at Ragland's, and the doctor had told him to 'get some of her things' while waiting for her to wake up – likely more as an excuse to get him out of the hospital rather than any real sense of concern for Dana's comfort, but it was as good a purpose as any for now.

Keeping his memorized map of the city in mind, Alex was planning out his route when the public payphone he walked past began to ring.

Flinching, Alex looked around hastily, then under the payphone. Stuck to its metal base was a familiar, slim black shape.

So the Hunter had survived. Somehow, Alex wasn't entirely surprised – after all, he had regenerated from almost nothing, after being caught in the blast. Reaching under the payphone, Alex snagged the mobile.

"What do you want?"

"You're still alive. Good." The Hunter was still using Cross' voice, if without the modulator. "I have a proposition."

"So do I. Tell me where you are, and I'll make sure you're dead this time when I'm through."

"Has your 'sister' woken up yet?"

Alex growled, as the skin under his nails crawled, itching to warp in to claws. "None of your damned business."

"She has a natural semi-immunity. She's fighting off the infection, but she might not wake up; not without a serum. I can arrange that for you."

"I know what you are. If you think I'm going to buy into any more of your-"

"I know that Doctor Ragland is your acquaintance. Ask him for the nanotech stabilizer, a syringe of it. In return, I'll give you the serum. You can have Ragland test it if you don't trust me. When you have the stabilizer, call me back on this mobile."

"Ragland is making a vaccine for my sister. I don't need your help."

"How long will the vaccine take? And how are you to know there won't be side effects?" 'Cross' pointed out calmly. "Talk to Ragland. Call me back when you have the stabilizer. Cross out."

One of humanity's most pervasive traits, Alex felt, as he stared at the black, inert mobile phone in his palm, was its original sin, curiosity.

II

Ragland looked unsurprised to see him. The Doctor's eyes were red-rimmed and puffy from lack of sleep, and he smelled of bone-deep weariness, old blood, and the faint thread of fear that Alex was used to among humans who understood him for what he was.

Most humans.

"Was wondering when you'll be back," Ragland muttered, examining a slide under a microscope. Beside him, on a bloody autopsy table, was a naked male cadaver, sliced neatly open. The lab stank of formaldehyde, blood, sweat and the rotting contents of digestive organs.

"Where's Dana?"

"Still sleeping." Ragland said, looking guarded. "She was exposed to the virus, Alex. Not a big exposure," he added hastily, as Alex took a step forward, "Not enough to turn. I'm synthesizing a vaccine based on what you brought to me the last time, for your cure, but-"

"But you need more genetic material?" Alex said, resigned, Cross' offer weighing on his mind.

"No. Just more time." The doctor placed the slide carefully onto a boxed set, and picked up another one. "Whatever you did, I hear the infection in Manhattan's been contained. Being cleaned up." Grudgingly, "Good work."

"If you say so." Alex tried to analyze the sudden, faint sensation of warmth in his abdominal area at the praise, and as he tried to dredge context out from the stolen memories archived in his mind, the doctor continued to chatter.

"Can't say I agreed with your methods," Ragland peered into the microscope again, "But I can't say there weren't mitigating circumstances. I don't have anything for you to do right now."

"I was asked," Alex said, watching the doctor carefully, "For a 'nanotech stabilizer'. A syringe of it."

Ragland's fingers froze over the slides for a heartbeat, and then he straightened, pushing his glasses up his nose. "And who asked you for one?"

"One of the infected." Briefly, Alex related what he knew about Cross – and the incident on the ship when he had realized that Cross was actually the Supreme Hunter.

" 'Supreme Hunter'? Ran out of inspiration for names, did we?" Ragland turned back to his microscope. "An infected wouldn't ask for the nanotech stabilizer. I wasn't aware that the Wiseman team was in Manhattan. But I guess it was only to be expected."

"Explain."

"The Wiseman team consists of modified Blackwatch soldiers. Not exactly like the supersoldiers, but similar. They're search, kill and suppression elites, made for hunting runners or dealing with outbreaks, enhanced by the most cutting edge nanotech available. If they're consumed, the nanotech is meant to cause a brief and very fatal chemical reaction with the devourer's nervous systems, and then self-destruct. It's to prevent any runners or infected from assuming a Wiseman team member's enhanced training and specialized memories. It's also to ensure that they complete their objective at any cost."

"And the stabilizer?"

"I was part of the team that developed it," Ragland said wearily. "Sometimes the nanotech wears down, becomes self-hostile. Causes pain, hallucinations, loss of control. The stabilizer suppresses it for another period of time. The entirety of the Wiseman team is hooked up on stabilizers. It's their leash. An infected wouldn't ask for the stabilizer, because an infected would already be dead."

"The Supreme Hunter isn't an ordinary infected." Alex frowned. "And it consumed Cross."

"Obviously the nanotech's killswitch didn't work on it. But why would it want the nanotech in place? If it can reform and rebuild itself from base material, it can reject the nanotech." Ragland pointed out. "And it won't need the nanotech's enhanced speed, strength and senses. It's more likely that you ran into someone else from the Wiseman team, posing as Cross. They're a well-trained extraction strike team. Voice modulators are the least of their abilities."

"Then it's possible that they have a serum that can help Dana."

"I'm not aware of a synthesized cure by GENTEK," Ragland said slowly, looking thoughtful. "But I left GENTEK a long time ago. If anyone down at ground zero has a proper, localized cure, it'd be a member of the Wiseman team."

"So you're saying I should trust this person."

"I'm not. But I'm sure that you're more than equipped to address any… eventualities." Ragland shot Alex's fingers a meaningful stare. "Go back to the GENTEK building. You probably have more recent memories than I regarding where their stores are. I'll give you a shopping list. Come back with the materials and I'll prepare a syringe of the stabilizer for you."

"All right." At the worst, if this were a ruse, the world would just be less one further Wiseman soldier. "Can I see Dana?"

Ragland scribbled something on a journal, tore it off, and handed it over. "You want to see your sister, she's down the back, but since her immune system's already busy fighting the virus, you might want to, hell, wash down first or something. I would suggest suiting up."

Translation: You are a host of infectious zombie-inducing diseases; please do not go near sick people you care about.

Alex tucked the scrap of paper into his jacket. "Maybe later. I'll go get the things you need."

"Might want to do it quickly," Ragland said mildly, scribbling in the journal again. "If whoever it is needs you to bring him the stabilizer, he might be a little far gone."

III

Breaking into GENTEK was the easy part. The facility was crawling with GENTEK personnel, slowly sifting through the rubble. After Greene's accidental release, it looked like the facility had been compromised by infected, possibly driven by Greene's instinctive wish for vengeance on her tormentors, and rotting gore and fleshy creep on the walls fought a slowly losing battle with GENTEK personnel.

Alex had absorbed the guise of a security guard, cradling a rifle in his arms as he ascended a stairwell, dredging stolen memories for the location and passcodes to GENTEK's stores. Surveyors and construction workers squeezing past ignored him, likely assuming that he was on patrol; security seemed thankfully lax. The guards were mostly on the perimeter, watching for any infected.

Five floors and two corridors later, Alex found himself alone in a partially blocked off corridor. Debris from a partially collapsed ceiling and overturned desks sealed off the rest of the memorized route. Irritated, Alex looked around him quickly, then dropped the rifle, scaling cracked concrete and twisted fingers of metal up to the next floor. Crushed tiles, a dripping sink and an overturned refrigerator indicated that this was once a communal kitchen.

Alex glanced at the closed door, listened for voices, then manipulated biomass into his fists, turning his bones wider, denser, his flesh hardening into overlapping plates. The first slam of his fist against the edge of the floor crushed tiles into powder. By the fifth, he had managed to smash a large enough gap between the collapsed roof and wall debris to squeeze past into the rest of the corridor, but he knew from faint shouts that he had attracted attention.

Reverting his arms back to normal, Alex darted past vaguely familiar offices and cubicles, to a locked storage room. The first keycode he pressed in out of habit – his own – caused him to flinch as an alarm started to peal, picking up quickly in an answering echo around the building.

Great work, genius.

Swearing under his breath, Alex reformed his arm back to the biomass fist and punched the closed silver doors until they skewed open, revealing a room crammed with rows of shelves containing alphabetically labeled pills and drugs. Reverting back and twisting through, Alex ran an eye over the list of materials and began taking bottles off the well-stocked shelves, slotting them into one of the padded carrybags lined in a corner. He took as many as two bags would carry, slinging them on his shoulders as he stepped out of the room.

The voices were much closer now, likely investigating the gap in the floor above. Alex lined up against the nearest glass window, concentrated biomass into his heels, and smashed through.

Four blocks and two faces later, the wail of the alarm fading to nothing behind him, Alex slowed down from his dead run over and across the rooftops, and turned to head towards the hospital.

IV

Ragland had taken a surprisingly short time to mix up the synthesizer, muttering to himself over sterilized lab equipment all the time, until he had finally handed Alex a colorless fluid in a corked syringe. Alex had made sure that he was nowhere near the hospital when he used the callback function on the phone.

While listening to the ringing, he stared at the edge of the Riverside park, which dipped into the Hudson river. The park – and much of the walk towards it – had been quiet, shops either boarded up or smashed and looted, apartment blocks deathly silent and scarred with shells and claw marks.

Dana had still been 'stable' and 'still needed more time', Ragland had called it, doctor speak for 'not in danger, but I have no idea why she isn't waking up'. Alex wasn't sure why he – the Blacklight virus – still cared. Reflex, perhaps. Or the pervasive human need to be needed-

After the second attempt, the Wiseman soldier finally picked up. His voice sounded shallower than before, even through the Cross-modulator. "You have the stabilizer?"

"Yeah."

"Good." A shuddering breath. "Judging from the locator I put in your mobile, I'm not far from you. Grant's tomb. Visitor center. You might want to make it here fast, before I smash the serum."

Irritated at the threat, Alex sprinted in the direction of the domed tomb, circling it once he was close. The tomb had been left unscathed by the mayhem, ignored by both people and the infected alike. Alex ignored the stately, granite and marble structure, instead stalking towards the shuttered gift shop behind it, a squat block of glass promising tacky miniature keychains and shirts. The door was locked, and with the help of some concentrated biomass, Alex kicked it open, then instinctively formed his left arm into a bullet shield as a red laser point staggered up his chest.

In the darkness behind overturned shelves and tables, there was the faint gleam of light reflecting from the lens of a rifle sight, then a snort. "Come over here."

Warping his shield into the double blade in open threat, Alex did so, narrowing his eyes. In infected vision, there was a man-shaped form curled up against a shelf, neither in the flecked outline of a human or the colors of an infected, but something else, white and pale. A torchlight flickered on, throwing harsh shadows against a man in a gas mask and dark fatigues, a sniper rifle on his lap; a broad-shouldered man, muscular almost to the point of being heavily built, his chest heaving shallowly as though in pained breaths. Gloved fingers were clawing ineffectively at his jacket sleeve, trying with shaking fingers to roll it up.

Alex sighed, kneeling down and slicing the sleeve up to the man's elbow, then warping his blade back to fingers and holding the arm still as he drew the syringe out from its velvet pack and uncorked it. Dr. Mercer's memories found the vein for him, and practiced fingers shot up the stabilizer. The man shuddered violently in his grasp for a moment, dislodging the syringe, then slumped back against the shelf with a hollow sigh.

"Vest pocket, top right," the man rasped in Cross' voice. "The serum."

Alex located the vial of red fluid in the buttoned pocket, and wrapped it carefully in the velvet pack that had held the syringe, tucking it into the inner pocket of his jacket. "If it's a trick, I'll come back and kill you."

The man snorted, and for a moment, Alex was tempted to kill him anyway. He could smell blood; the Wiseman soldier was bleeding slowly through filthy makeshift bandages that wrapped over his left hand and over his left shoulder. Even wrapped up as the wounds were, Alex could identify the most likely source of the massive bites. "Are you going to turn?"

"The Wiseman team is immune."

"Then why are you carrying a serum?"

"Allies. Taggart. Others." The soldier was forcibly trying to slow his own breathing.

"You've lost a lot of blood. How long have you been here?"

"Nanotech," the soldier said, with a wet gasp, then grabbed at Alex's wrists as he reached for the mask, too weak to do much but dig nails into his skin as he formed fingers into claws and sliced the straps off, pulling it away.

"Cross?"

"Who in the world did you think it was?" Specialist Cross' eyes were glazed, but he still managed to frown. "Listen, Taggart-"

"I should have done more than just decapitate you," Alex growled, leaping back and onto his feet, biomass crawling up his wrists.

Cross stared at him blankly. "Decapitate?"

"On that ship!"

"Mercer," Cross said slowly, dryly, "I sure as hell would have remembered being decapitated."

Maybe you reformed." Alex said, if now a little doubtfully. Why wasn't the Supreme Hunter healing? And if Ragland was right, why would the Supreme Hunter absorb the nanotech? "You've been here all this while?"

"Few days. Team overwhelmed during the evac. Fought this… creature. Took a bite out of my shoulder and some of my fingers and smacked me off the building. Landed… some glass, some wire mesh… somehow managed to crawl someplace safe. I take it my team wasn't so lucky." Cross' voice was getting slowly steadier, as the stabilizer did its work. "Listen. Taggart might be planning on nuking the city. The coordinates of the ship are-"

It seemed that the Supreme Hunter had somehow managed to replicate Cross from just a minimum amount of genetic material. But then again, Alex reminded himself, he had regenerated from a crow, after being caught in a nuclear blast. He wasn't exactly a good judge of what was possible.

"Taggart's gone, and the nuke's taken care of."

Cross looked so surprised that Alex couldn't help but smirk. "Your doing?"

"Yeah." He wasn't above the human tendency towards pride.

"Not bad," Cross decided, gruffly, then he narrowed his eyes and scrabbled for his rifle as Alex hauled him up and slung him over his shoulder. "Jesus! Mercer, what the fuck do you think you're doing?"

"Shut up and stop moving or I'll throw you into the river," Alex said curtly. "I'm taking you to Ragland to get patched up. And then you're going to give me some answers."

tbc