Hello all! Sorry I've taken so long to update— remember that reviews are food and encouragement and all so many good things come of them. Like inspiration!

—

Several yelling matches and one whispered conversation with John later, the Doctor was re-released. Rubbing his wrists and giving Sherlock a resentful glare, he moved back to stand next to John. "As I was saying! The taikreng are fast-acting and growing, and a wrong move could be our last. Which is why I've been keeping them contained as best I can in here."

"There can't be parasites in those bodies," Sherlock said abruptly, scowling right back at the stranger. "Parasites live on the processes performed by live creatures. That's what it means to be parasitic. This is a morgue, if you haven't noticed." A flash of annoyance crossed the Doctor's face.

"It's complicated," he bit out, turning away from Sherlock. "More complicated than I can explain now, seeing as this is an emergency—"

"I'm very clever, I'm sure I could understand if it actually made any sense."

"Sherlock! Shut up!" John barked. His hands had balled into fists at his sides. The look Sherlock gave him was shocked. He tried to ignore the surprised expressions on the faces of the police, the hurt in his friend's eyes. "Look. We need him, he knows what he's talking about. Just listen."

"Actually, that's all for now!" The Doctor moved to the door, beckoning John to follow him. "We don't have much time so I'll just say this again: Stay put. Don't go in here unless you hear us screaming bloody murder, and even then, fight the impulse. Got it? Let's—"

"Hold on." Sherlock had crossed the room in a few long steps, eyes burning holes into the Doctor's, lips thin and white at the edges. "I'm coming too." He leaned forward slightly. "You know I'm smarter than them; whatever you did to that card— some sort of illusion or psychic trick— wasn't enough to trick me. Nor is it technology that would be carried by anyone civilian. Maybe not even human, though that hardly makes sense," he said, giving an obviously feigned huff of laughter. "I'm genius, an asset. I'm coming."

The Doctor straightened his shoulders, surveying the other man appraisingly. "So? I'm a genius myself. I'm very clever, much cleverer than you, and I don't much care for your patronization." There was a long pause. "I'm the one who knows what's going on here. Not you. Though, technically," he continued with a slight smile, turning toward John, "it was Doctor Watson who figured it out. Good on you for that, by the way, I should have told you back in the hall, but the circumstances were—" He pulled a face. "I knew you'd get it eventually."

Sherlock's eyes narrowed. "So if you don't want my help, why are you asking for John's? He's not a part of this investigation."

"Since when?" the Doctor countered, placing his hands on his hips, watching the other man closely.

"He's not a detective, or a policeman. He's just my assistant." Behind Sherlock, John's expression twisted and immediately became blank. Before, he'd been introduced as a friend. What the hell had he done to deserve this? Thrown out one too many experiments? Forced the man to watch a particularly awful action movie? A sense of dread crept down through his body, a slow sickening in his gut. As if something important was slipping through his fingers. Which, John noticed, glancing at his left hand, were trembling. Clenching the offending appendage, he considered punching the arrogant bastard— but there was much more than his pride at stake here. They were losing time.

"If you're done with your pissing contest," he cut in, "I think the Doctor and I have something that we need to attend to." He knew the tension in his face and shoulders was all too visible. John could see a flicker of recognition in Sherlock's eyes and, hard on its heels, something like fear.

"Quite right!" The Doctor moved away from the two of them, rubbing his hands a little as he walked towards the double doors. "You can come along if you like Sherlock, but I wouldn't recommend it. It's not really your field of study, what we're dealing with." Sherlock gave an audible sniff, looking away from John.

"I assure you, I'm quite capable of taking care of myself."

"Right, of course, that's why you need an assistant," the Doctor said politely, turning to smile at the other man. John couldn't help the snort that burst out of him, though he immediately placed his fist over his mouth. The smile slid towards him, grew into a happy grin. "John? Ready?" Grinning back, he nodded. "See everyone in a few minutes, if we aren't killed in the meantime!"

—

They slammed the doors open, the Doctor pulling out his cylinder as they did so and buzzing the nearest vines. "Some explanation, now that we're out of the vicinity of people who would most likely have a conniption fit if they heard what I'm about to say: these are aliens, not just parasites, I'm an alien, not just a doctor, and this is sonic, not just a screwdriver." John stared at the object in his hand.

"That's a screwdriver? Why do you have a screwdriver?"

"Well," he said, shifting a bit uncomfortably in his jacket, "for… screwing things. And other things! it scans and— and opens cracks in time-space— it's a multitool!" He shook it in John's face. "It's very important, alright? Does a lot of complex stuff."

"Like acting like a dog-whistle for parasitic aliens," John said, the corner of his lips quirking as the Doctor huffed.

"Yes! Exactly! Very important!" The man straightened a bit. "Though it doesn't work on wood."

"You were giving an explanation," Sherlock said pointedly, expression stiff as he watched the pair of them.

"Right, yes—" Spinning on his heel, the Doctor directed his glare back at the busily moving creatures. "These are taikreng, an intergalactic and sometimes inter-dimensional species of nomadic parasites that feed on the consciousnesses of all bipedal creatures and use their bodies as their homes and eventual mating grounds, discarding them when they have outlived their usefulness and using them as a jumping point for other infection. Which means, as you pointed out earlier—" the Doctor moved forward and knelt by the vines "— that the bodies currently in this morgue are not dead."

Standing again, he moved down the hall, directing his sonic screwdriver this way and that. "They're both being kept alive and being drained by the taikreng, who have staged, quite nicely, a series of serial killings."

"Why?" John broke in, brow furrowed, bewilderment clearly written across his face. "I mean, what's the point of that?"

"Disguise!" The Doctor's statement was more like a crow, admiration tingeing his voice as he fired off another sonic blast. "They've been running for a while, this lot, and they know that people are looking for them, myself included. See, they usually have a pattern: they infect one person, get them sent to the hospital, and then proceed to infiltrate the entire facility, moving out from there. It's easier— they're capable of moving the body they're in to get at a new victim, but it takes a lot of effort. Why walk when you can simply build a neighborhood from rows of hospital beds?

"Only problem is that it's a calling card now." They were getting closer to the morgue now, the vines actually parting before them, sliding back to their source. The Doctor frowned at the doors, half ripped off their hinges by the force of the vines' pursuit. "An entire hospital in a coma? Pretty obvious sign of alien incursion."

"So they damaged their hosts to make it look like they'd been murdered, gestated in the morgue, and are spreading through the staff?" Sherlock breathed, watching the bizarre animals' retreat with fascination in his eyes. "Ingenious."

"Just buying themselves time," the Doctor said grimly. "They know they're not allowed to be here." Pushing open the door leading to the stairs, he led the way down into the morgue, John pulling out his gun as he followed close behind. The bloody mess that was the body of the guard lay oozing on the ground, the vines crimson where they had passed through the gore.

"Wait," Sherlock muttered, "the thing I didn't almost see—"

"Perception filter," John murmured back. Sherlock's head jerked towards him and he shrugged. "That's just what he said. Some sort of psychic block that keeps you from really seeing them. I'm sure you'll understand it better than I do."

"Inevitably," Sherlock said, voice clipped. They stared at each other for a few seconds.

"Taikreng people of the planet Zolfate, you are guilty of violating Article 86 of the Shadow Proclamation— you cannot seed on a primitive planet not fully integrated into the galactic civilization." The Doctor's voice broke through the tense silence, strong and grave. As John's eyes turned back to the man, he saw in the Doctor's expression and posture a heavy resignation. His eyes, so full of life minutes before, were dead and weary, his shoulders bent with some horrible knowledge. An understanding of what was to come. "Furthermore, you are charged with the destruction of the civilizations of star system 78201 and the Trimaltiran colonies in sector 930, among other crimes."

"Is this to be our trial, Doctor?" The response did not seem to be aural, but rather sounded in John's mind. It was full of pain, the pain of centuries, of generations living on wounded pride and desperation. It had an edge to it that was wretchedly mocking. He hoped he only imagined that he saw the Doctor flinch. "If you were to as just as you act, you would provide us with our assembly of equals."

"You know you have no support," the Doctor countered quietly. "You destroyed several well-established homespecies, that's much different than living on bipedal livestock. They won't accept your testimony."

"We've both committed genocide," the voice said, and John's eyes darted to the Doctor's face. "Why has no one put you on trial?"

"What I did was for the best."

"The best for who? The Saturynians, the Gelth. The Racnoss. So many dead. So many left without a home. Who bettered from your slaughter?" The voice grew deeper. "Certainly not your own race."

"It doesn't have to happen again." The Doctor took a step forward, his expression pleading, clearly hoping against hope. John tightened his grip on his gun as the vines pulled away, moving to slide around the Doctor, encircling him. Sherlock, however, scrutinized the man's face carefully, holding up a hand to John in warning. "I know you don't trust me," The Doctor continued, "I don't expect you to. But I also know the entirety of time and space, all that was or ever could be— there's more than one Zolfate. I can find you a home!"

"You do remember that these things have killed at least five people?" John's voice was low, guarded. He was out of his depth, but this wasn't right; those people had families, lives. "You can't just forget that! You can't let them walk away and give them a home—"

"This is not a matter of justice, Dr. Watson!" the Doctor shouted, barely turning to look at his companion. "It's much more complicated, and ancient, than you can ever imagine. This isn't about justice, there's nothing just about the situation." Slowly, he looked back towards the vines. "This is about an old debt. And a lot of forgiveness."

"Forgiveness for whom?" Sherlock moved forward, peering into the Doctor's eyes, his own expression knowing, even dangerous. "Doctor, what have you done?" he asked quietly.

It happened so quickly, John wasn't even sure if he had truly seen it. His heart still sick with the implications of Sherlock's words, he had barely enough time to register the vines' change in direction and focus, bellowing some incoherent warning to his friend even as the creatures wrapped around him, pulling him back towards the guard's remains. Wild-eyed, he shot a look at the Doctor, who was already raising his screwdriver, yelling at the taikreng to put Sherlock down. "Convention 15 of the Shadow Proclamation, there is a cessation of hostilities in order to parley! This man is an observer, a bystander— you cannot touch him!" As the Doctor shouted commands, however, John could see the creatures gathering around Sherlock, who struggled and twisted their stalks in vain, desperation mounting as he realized he could not escape. John's pulse was pounding in his throat, nausea swelling as he raised his gun and realized he had no idea where to shoot. It was the pool again, but worse, much worse, because it was loud and fast and no one was doing anything—

"Doctor!" he yelled in his fury, the word exploding from his lips. It seemed to bring the man to his senses and fill him with purpose.

"I demand that you release Sherlock Holmes of 221B Baker Street, planet Earth." A low chuckle resounded inside John's head, its depth almost painful, and the Doctor's expression became enraged. "You must release this human under Convention 15—"

"But these are not hostilities." The voice spoke softly, a single vine laden with spores rising up between the three of them. "This is not even a usurpation. How can it be, when they continue to live and walk throughout this planet? This is… cohabitation." The petals around the spores were peeling back, retreating. Revealing an inside multi-hued, the deepest part a dark burgundy, gradually blending with an emerald green, the spores on stems so delicate that they seemed like spindles. And John understood that this thing of beauty would have to die. Because between it and Sherlock, the sociopath was the heartless creature he minded least.

"Sherlock, duck!" he yelled, shooting the heart of the vine even as his friend jerked out of the way. The noise in his head was unbearable, an agonized scream that made John gasp for breath, stumbling forward blindly— he couldn't see, there was too much pain in his mind, in his bloody fingertips, he was choking on something, couldn't breathe— and he could hear the Doctor's screwdriver, and the cries only became higher, louder— "Ahhhh!" He dropped the gun, clutching at his head, and felt arms surround him on either side, pulling him up, out, away from the strong, thick vines that wrapped around his legs and his throat, choking him even more, away from the voice shrieking with fury.

"They're activating the others—!"

"What does that mean?" The two shouting, familiar voices cut through the noise, the deeper baritone somewhere near his head. Hearing it, John reached out, grabbed onto the person's arm, held it as tightly as he could. He was going to die, he could feel it moving inside him, coming for him—

"In here!"

"What?"

"Just get inside!"

And suddenly all was silent inside his head. Breathing shakily, John could hear footsteps thudding beneath him, carrying farther inside this sanctuary. "How does it work?" Sherlock's voice was close, very close, and sounded awestruck, but John couldn't open his eyes. The pain hadn't disappeared; if anything, it was growing. He barely held back a cry as they lay him down on something hard, cold, and metallic. The high-pitched whine of the sonic screwdriver passed over his face and the agony intensified, spiking suddenly and hard enough to make him scream. Every muscle convulsed; he could feel his back arch and fall as the spasms shot through him, his fists clenching, his nails biting into his palms and drawing blood. The world became a white haze of anguish, ending only when the sonic fell silent. He could hear the Doctor's breath catch, felt the man's callused hand press against his forehead. "What's wrong with him?" Sherlock's voice was shaking.

"There's a spore inside him." The Doctor stood and began pacing. "If we don't do something, and fast, John Watson will be the first casualty in this war."