An Unknown Intruder

The creature boarded the Normandy without anyone realizing. Where precisely it had come from and how long it had been on the ship were questions without answers. Was it even alive? Unclear. EDI certainly never detected any additional life signs on board the Normandy. What was clear was that it was unlike anything ever seen before in known space. It looked like a living pool of liquid mercury, all shiny and silver, and it interfered with nearby electronics when it passed. While slow, it appeared there was no crack too narrow for it to slip through, and it showed demonstrable intelligence, creeping through the ventilation system and other nooks and crannies to remain undetected until it finally found a target.

Miranda was in her office, filing a field report with Cerberus about their latest excursion. No doubt Ashley Williams was doing the same for the Systems Alliance, with ample additional notes about how Cerberus was plotting against them. How juvenile. Miranda knew better than anyone how vital this partnership was to the Illusive Man. It gave him eyes and ears in places previously inaccessible to the likes of them. She was careful not to reveal too much, she didn’t want Shepard to eject her from the ship for leaking information, but she kept them informed.

She didn’t noticed the creature seep out of the vent. She didn’t notice it crawl along the floor towards her. She didn’t notice anything amiss until it was too late. It lurched upwards, casting a shadow over her just long enough for Miranda to turn and look before it fell upon her, submerging her instantly in its silvery mass. She struggled, trying to claw out of it, but it restricted her movements, shifting and changing, thickening and hardening wherever necessary to prevent her from escaping. Then, her movements became weaker, the form of Miranda began to slow and thin as the creature broke her down molecule by molecule, absorbing her body, and digesting her mind. After a few short moments, only the puddle of the silver entity remained.

Then, it began to ripple and contract, gradually reorganizing itself into a familiar shape. The outline was instantly recognizable even without proper defined features, as her figure was always unmistakable. Once a mold was in place, the fine details came next. Eyes, mouth, nose. Then it began to flush with color and texture, creating an approximation of silky skin. It lacked nipples or an open slit, though the curves were all mathematically perfect, just like the original. It materialized clothing on top of its skin, giving it just enough give to appear real. Finally, it worked on the hair, growing it back to its original length and luster, only instead of black, it came out a brilliant shade of vibrant silver, the same color as her newly tinted eyes.

“Operative Lawson,” EDI chimed in. “I apologize for the intrusion, but my systems detected your vital signs fluctuating before they suddenly disappeared. My visual feed is blocked by some kind of electromagnetic interference. Is everything all right? Do you require medical attention?”

Everything Miranda ever knew circulated through the creature’s mind with perfect clarity. It did not understand the information per se, it did not have ideas of its own, but it did have instincts. Instincts which recognized inputs and outputs, and thus could mimic the fragile art of conversation. It simply needed to connect the correct words to each other in order to produce a positive result based on the countless previous interactions of Miranda Lawson with others. Like a dog learning to sit in order to get a treat.

“I’m fine EDI,” it said, in as pleasant and casual a voice as Miranda could have ever managed. “There’s nothing out of the ordinary going on down here, though if you’re having issues, you may want to run some diagnostics on yourself.” This creature, unfortunately, had more complex instincts than any animal ever encountered in known space.

“A repair cycle would take several hours. I would be offline in that time frame.”

“Well turn the ship over to autopilot and get to it. We’re in no hurry right now, right? And we can’t have you glitching out when we are.” It’s impersonation was flawless. The enunciation of Miranda’s accent, her vocal tics, her mannerisms, all of these were instinctively applied. “Shepard would say the same.”

“Based on past experience, I believe you to be correct. Very well. Autopilot engaged… Initiating repair cycle in 3… 2… 1…” The voice clicked off. Anyone else might have felt satisfaction from such a deception, but this wasn’t anyone. This was a creature operating on instinct and drive. Now that it had successfully infiltrated the ship and assimilated a host form, as it had been driven to do, it’s new drive was to replicate and reproduce. It sifted through the memories of Miranda, looking for an ideal candidate, and within moments it found one. It walked forward, reached the door, and slid through the cracks. Before it reemerged on the other side, it sensed for anyone who might be watching, but no one was. Everyone was asleep for the night cycle. This one had been working late. It slipped through and reformed into Miranda on the other side, walking to the elevator, passing through it, and slipping down the elevator shaft to the engineering bay.

…

Jack was asleep, naked in her cot, when she heard the footsteps moving down the stairs. It was dark, but even from where she was sitting, she could see the familiar buxom outline of her hated nemesis, “Little Miss Perfect” Miranda Lawson. She stood straight up, letting it all hang loose. She didn’t give a shit if Miranda could see her snatch or her boobs, if anything they gave her the chance to show off to the ‘perfect woman’ what real beauty was. The harsh realism of it all.

“What do you want you cheerleading bitch?” She growled. Miranda did not reply, instead she simply walked a little closer and stopped. “Whoa,” Jack said audibly, before grinning like an idiot. “Pfft. What the fuck happened to your hair? You fucking bleach it or something?” Jack chuckled.

“Do you like it?” Miranda asked. Jack’s grin faded, and a bit of red flushed into her cheeks.

“I… What?”

“Do you like it?” Miranda asked again, not missing a beat.

“I… I mean it… Um… Is, uh, is this some kind of trick? Some kind of Cerberus psy-op or some shit?”

“No,” Miranda replied. “No tricks. I just want to know if you like it.” Jack stared at her, then swallowed. There was something in her voice, something in her eyes, a sincerity that Jack had never heard before, and it took the wind out of her sails. She felt she had **** but to be honest, both with Miranda and with herself.

“Yeah… Yeah I do. It looks good on you cheerleader,” she said, cocking a half grin, trying to regain a little edge. Miranda smiled, causing that grin to fall away immediately. This was weird… so why wasn’t Jack stopping it?

“I’m glad you like it Jack,” said Miranda. “I did it for you.”

“You what?” This had to be some kind of trick. This had to be.

“I’ve had a lot of time to think Jack, about us, and I think I owe you an apology. I’ve said some terrible things to you, never once trying to understand you…” She stepped closer, and placed a hand on Jack’s shoulder. “I’m sorry. I… I would like to understand you better. A more… intimate understanding.”

Jack’s brain practically short circuited as Miranda’s hand glided up to her cheek and began to caress it gently. This couldn’t be real. Was Miranda coming on to her right now? Since when was she into girls? More than that, was Jack actually falling for her? She hated her! None of it seemed right, yet Jack couldn’t help but melt.

“O-Okay…” Jack stammered. “I guess… that… would be…” She drifted off as Miranda took hold of her face with both hands, leaned in, and kissed her. Jack returned it willingly, unable to resist the strange hold Miranda had over her. She had no idea what was about to happen.

The creature that had replaced Miranda did not feel satisfaction as it was incapable of such things. However, it had directed its electromagnetic power at Jack, altering the electrical impulses in her brain to deprive her of rationality and suspicion, and replace it with animalistic lust. The creature needed to reproduce. Jack now needed to fuck. This was going to work out just fine.

Jack took hold of Miranda, her hands falling down her back as she felt her way across Miranda, admiring the curves and the skin she had long admired, even envied. She felt Miranda do the same, exploring her body, her hands running across her back, her chest, her ass. They broke away from the kiss just long enough to free themselves of the rest of their clothes, before their lips pressed together again as Jack brought Miranda to the nearby cot. They lay down in each other's arms, and began to kiss passionately.

It was when Miranda rolled on top of her that Jack was doomed. Jack only barely had time to realize something was wrong when she saw Miranda’s featureless naked body, but before she could truly process that information, Miranda had fallen upon her and stuck her tongue down Jack’s throat. Jack’s eyes went wide, then her eyelids fluttered and her eyes rolled back in her head as the creature pumped more and more of itself into her body. Jack’s mind was dulled from the strange sensations the creature was filling her mind with. She could feel it disrupting her consciousness, subsuming it. It wanted her body and mind, but her soul was a needless burden. She was just raw materials to it, something it could consume. She would be absorbed and reconstituted so that the creature could reproduce.

It wasn’t long before Jack simply melted down into a puddle of silvery liquid, which Miranda quickly began to pull into herself through simple contact, like a sponge absorbing water. If EDI had still been on line, she'd have seen more vitals disappearing. Miranda stood up, her discarded clothing melting down into silver, devouring Jack's discarded clothing in the process, and then crawling back to be reabsorbed. Miranda's clothing reappeared on her body, and once it did, the outline of her body began to fray. Strands of silver crawled off of her, forming into another feminine shape next to her, this one shorter, less mathematically precise. Bit by bit, the process played out again. First a silvery body, then the fine details, then the colors (in this case, a myriad of vibrant patterns to match her tattoos), then the clothes, then silvery hair, although in Jack's case, it was only visible on her eyebrows and a slight shimmer across her shaved head. The doppelganger opened her silvery eyes. The creature had replicated and replaced another. They were not separate entities exactly. The two bodies were in constant communication, exchanging all visual and auditory stimuli, with the collective knowledge of both women completely accessible to both to ensure they were fully capable of disorienting, confusing, and ultimately subduing their prey so they could spread further.

And spread they would...