Author's Note: Again, I am not a biologist! I am just making this up as I go!

"Padok?"

"Mordin. Hello. I didn't expect a call from you."

"Have question. Near relay for call reception. Busy?"

"No… no, I suppose not. Not right now. How can I help?"

Mordin paused, then continued at rapid speed. "Remember idea about Collectors? Monoclonal antibody technique to counteract sodium channel blocker? Synthesized dose. Tests run. Having problem with allergic reaction."

Padok was silent for a moment, then Mordin heard him shift on the other end of the line, and the audio quality changed - suddenly he sounded much closer. "Reaction?"

Mordin winced, but continued. "Tested on self. Triggered histamine reaction causing activation of grip pads, blood pressure drop, itching, trouble breathing - typical anaphylaxis."

"You tested this on yourself?" There was a static noise as if Padok were dragging fabric over the microphone. "Are you mad?"

Mordin opted not to make a joke. "Had backup." Another wince; bad choice of words. "Had help," he amended.

"Anaphylaxis isn't something to mess around with. Especially not salarians - you know that!" Another static noise.

Mordin paused. "What are you doing?"

"Walking. Sorry, there's a breeze."

"Anyway - know that. Okay." He inhaled sharply. "Would prefer to focus on allergy solution."

"Okay? You're infuriating, and I'm glad I don't have to deal with you any more, you know that?" Mordin snorted. "And… you don't have time for gradual exposure, do you," Padok continued.

"No." Mordin leaned on his workbench, resting his elbows on the hard plastic. "Antihistamines interfere with effectiveness, too."

"If you can avoid the anaphylaxis somehow, my first guess would be some form of additional antibody injection."

"Don't have additional antibodies," Mordin mused, and he heard Padok make a noise of agreement.

"Yeah… I'll think about it. But you mentioned your grip pads. I've never heard of an allergy causing that. Are you sure that's a symptom of the allergy, not a side effect?"

"Quite," Mordin murmured, flipping open his display and riffling through the available information. "Did tests. Blood tests, skin prick tests, antibody measurements… Appeared to be related to muscle stiffness."

"Did you have muscle stiffness anywhere else?"

"Mild. Not much."

"That would require a lot of - ouch!" Padok yelped, and Mordin heard more static.

"Padok?" Mordin waited, the line silent. "Padok. Can call back if needed."

"No, no - I just, uh, tripped over something," came Padok's voice. "Sorry."

Mordin paused. "No trouble," he said after a moment. "Ideas?"

"Mordin, I - " Padok sighed. "Anaphylaxis is just one of those funny ones. If you don't have a pattern to, well, pattern from in order to prevent it, you're stuck."

"Hence, calling you for ideas."

"You don't have anyone else you can call?"

Mordin paused again; the customary wry tone was absent from Padok's voice. "Skilled biologist. Trust opinion. Why? Prefer I call someone else?"

"I'm just…" Another pause; more static. "I said I wasn't busy, but I am a little distracted. OW - "

Mordin heard a series of thumps; it sounded as if Padok had dropped his communicator. "Padok?"

"Yeah, give me a - shit, Mordin, I'll have to call you back. Bye." With that, he hung up.

Mordin blinked, taken aback at the abrupt ending to the conversation; nonplussed, he began scrolling through the available information on his display again.

Antibody treatment. Hm. Even if he didn't have a method to generate antibodies for this specific reaction, he could try to identify the exact method of action and go from there. He flicked the display, opening up a new log, and typed in some information.

Date: 2186, Jun. 3, 22:24

Log: 2616

Entry: 3

User: Solus, Mordin

Experiment: Blood test running panel of antibodies; will subsequently test against swarm venom antidote.

He leaned back, stretching, then walked around the worktable, collecting a rack of test tubes from the lab refrigerator, and began setting up the experiment: swabs, an elastic band, a needle to draw blood, some antiseptic.

Right as he was about to slip the needle under the smooth skin on the underside of his forearm, his omni-tool flashed.

"Yes?"

"Hey. Sorry about that." Padok's voice came through his shoulder frame's speakers, still staticky.

"Out of breath?" Mordin inquired, the needle hovering over his arm.

"Did you consider creating an isolated system to try to reproduce the anaphylaxis?" Padok didn't even bother sidestepping the question gracefully, instead opting to bluntly change the topic. Mordin raised his brows.

"Topic avoidance. Conclusion: busy. Will call back later."

"Wait!" Padok's voice came through the speakers, tinny and loud. "It's fine, okay?" He paused. "I'd say I'll tell you later, but I probably won't."

"STG work," Mordin surmised.

"It's complicated," Padok answered immediately. "But listen to me - I need you to not hang up, actually. You might make this easier on me."

Mordin tilted his head to one side, interested. "How so?"

"Um… That I actually will tell you later. Just stay on the line - ack!" Another bout of static, and Mordin heard someone - with a deeper voice than Padok's - let out an oof. Padok came back on the line, still slightly breathless. "Just keep talking. You were going on about allergies?"

"Allergic reaction to swarm venom antidote compound," Mordin said conversationally, leaning forward with the needle at the ready once again. "Quick blood test. Hold on." With ease borne of practice, he slipped the needle in, then pulled the elastic band off his arm and flexed his hand. "Yes. Have run antibody panel before; will run again, see if anything turns up."

"You don't have any samples from the time you did that initial test? The one that caused the anaphylaxis?"

Mordin rolled his eyes. "Don't lecture."

"I'm not! It was an honest question." Padok's line went staticky again, and Mordin heard distant voices. "So - the blood test. Can I make a suggestion?"

"Of course."

"Run it through a dialysis machine with the filter set to antibodies, with dynamic range."

"Category too wide, and filter would catch cells before antibodies."

"Not if you centrifuge the plasma out first, obviously. Then narrow it down with an exposure test. Do a skin prick test, scrape off the affected skin, and see if you can extract any information to compare it. Only I'm not sure how you'd extract it."

Mordin stared off into space, running the scenario over in his head. "Not bad idea." He hummed, continuing to think. "Protease-type enzyme targeting non-antibody material?"

"Do you have the time to create that?"

"Won't start from scratch. Have samples from husks - protease used to break down protein chains during initial transformation. Selectively."

"Husks? Wait - those dragon's teeth things? Ugh." Mordin could almost hear Padok shudder through the line. "Those scare me."

"Not good," Mordin murmured in agreement, then quickly pulled the needle out of his arm one-handed and slapped a piece of gauze over it. "Will try dialysis idea."

"Good. Okay - stay on the line, I have to go dark for a moment." The line went silent.

Mordin carefully taped the gauze to his arm, then began putting away the test equipment, disposing of the needle, and tilting the test tube upside-down several times before clicking the newly-filled tube into the centrifuge while his mind wandered.

Protease-type enzyme. The dragon's teeth, as humans called them, used an enzyme to selectively break down proteins while leaving certain structures intact, ready for the Reaper tech to twine through it, corrupting their victims. Horrible fate, he mused. Perhaps he could figure out a preventative measure for that, too.

He had just sat down to enter more information into the experiment log when Padok returned. "Hey! Thanks for waiting. Can you do something for me?"

"Of course. Within reason," he added, and Padok chuckled.

"Within reason. Okay, I need you to look up a sufficient frequency to block an echolocator with a frequency of 100 kilohertz."

Mordin paused; was this a trick question? "100 kilohertz?" he offered, and Padok snorted.

"No, I need you to play the noise. My omni-tool's jammed."

"Oh." Mordin hummed as he set his own omni-tool to play the required noise, then directed it through the line. "Say when."

"Any time."

"Starting now," he said, and started the sound generator. No audible sound came out - the range was outside of either of theirs' hearing. There was, however, suddenly a series of scuffles from Padok's end of the line, along with a huffing Mordin recognized as a running pace. "Padok?"

"Give me a second." The huffing died down, and Mordin heard him grunt with effort. "Okay. Good. Can you pause it?"

Mordin complied.

"Thanks. That just made things a lot easier."

"Of course." Mordin paused, then asked, "Won't give details?"

"No. Sorry," he said sheepishly. "Not yet, anyway. You may end up with access to the log files when I'm done."

"Fair enough."

"So, your little allergy project. How quickly do you need this done?"

"As soon as possible."

"No real deadline?"

Mordin hesitated. "People dying. Longer it takes, longer that goes on."

Padok was quiet, then said, "Ah. I see."

"Collectors not a very lenient group."

"No, I'd suppose not." Padok sighed, and Mordin heard him shuffle around. "How long can you stay on line?"

"Few hours."

"I won't need that long. Can you look up a plant species for me?"

"Of course. Name?"

"Ah. Don't have one. My omni-tool - uh - let's just, er, say the whole database got messed with."

"'Messed with?'" Mordin echoed.

"Tell you later. Plant now."

"Mm. Description?" Mordin asked.

"Um… Coppery. Vine. Very thick - the stem at its base is nearly two feet wide - and very tall. Can grow to heights of a hundred or more feet up, and that's just what I can see. Iridescent leaves, three pointed sections to each leaf."

Mordin input the data into his omni-tool, which rapidly spat out several options; he ran through the pictures. "Jagged edges on leaves?"

"Yeah."

"Sennive plant. Native to - "

"Don't!" Padok's voice rang out, nervous and high-pitched. "Don't say it! I mean - just tell me if it's edible. That's all I need to know."

Mordin scanned the encyclopedia entry, picking out relevant information quickly. "Yes, but will cause upset stomach to salarians. To most species, apparently. Leaves can be made into salve for irritation or wounds that do not break skin, however."

"Good enough." Mordin heard a curious ripping noise.

"What are you - " he began.

"Can't, Mordin. Look up the logs when I'm done. You know how long it usually takes for STG files to be available."

"Yes, yes," Mordin muttered. "Anything else?"

"Not yet. Don't sign off yet, though."

Mordin paused again as an idea struck him; Padok had sounded almost panicked when Mordin almost let slip the native planet, which implied… Was somebody listening in? He drummed his fingers on the table, thinking hard. "Nevertheless, how have you been?" he asked, his voice somewhat stilted.

"'Nevertheless?'" Padok echoed. "I mean, as all right as can be. Distracted, like I said. I've been busy."

"Guess what I am doing?"

There was a brief silence. "Tests, I assume."

"Extracting antibodies."

"Yeah. Tests. Are you using the dialysis method? You can't have spun it through the centrifuge yet."

"Detect abnormalities," Mordin continued, leaning his elbows on the workbench.

"Already? Really?" Padok sounded doubtful. "How obvious was it?"

"Bad results."

Another pause. "That obvious?"

"Poor strategy."

Padok was quiet for several seconds, then quietly said, "Yes. Yes, that's too bad. Yes, I'll review the files if you like - that would help, yes?"

Mordin nodded, thinking quickly - luckily, Padok had deduced the code hidden in his speech. "Of course. Will send when I can. Hopefully - message received quickly." He hastily opened his display and began to type. "Bored," he stated. "Want to play a game?"

He heard Padok hesitate. "Uh… Sure. I've got time, I think. Wouldn't hurt to pass the time. What are you thinking?"

"Chess."

"Easy enough." There was a tapping noise as Padok presumably pulled up a chess board. "Verbal chess, I'm guessing."

"No. Will send moves."

Another pause - then another click. "You won't be able to send a file that big."

"Try anyway." Mordin tapped the display, which did not show a chess board - instead, it showed a complex chart of frequencies and code, which he packaged into a file as tightly as he possibly could. "Sending first move."

"I'll stand by. This may take a while."

Mordin hit send.

"So how have you been? More teaching Covus to your little chess protégé?"

Mordin chuckled, his eyes not leaving the upload status bar. "Yes, and no."

"Is she getting tired of it?"

"No," Mordin assured. "No… Strained, right now. Mission went badly."

"Ouch. How badly? Did she get hurt?"

"Ah." Mordin winced, debating whether or not to disclose any of his ill-fated experience. "Few injuries to crew members. Crisis averted," he said vaguely.

"Ah. Well, hope they heal quickly."

"Thank you."

"Oh, hey - I think I'm getting a bit of that chess move. The file size is - " Padok cut off mid-sentence, and instead quickly said, "This is, uh, going to be one slow chess game, huh."

"Yes," Mordin said absently, watching the upload status as it slowly ticked up. "Not in mood for verbal chess."

"Too bad. Aha - I think it sent. Let me, um… open my chess board." There was a series of rapid clicking noises, then a sound like a foghorn, and Mordin distantly heard Padok let out a yell.

"Padok?"

"Hell, Mordin!" he said crossly once the ringing sound left behind by the foghorn noise stopped. "All you had to do was compile the firewall code!"

"Cover tracks," Mordin said smoothly. "Loud noise may appear to be an accident to any hackers. Buy you time." He paused. "Line still hacked?"

Padok tapped his omni-tool in a series of clicks again, then said, "Nope. Thank you - I got hacked as soon as I landed on this planet. Nice trick, sending me that firewall code - but that noise means I've got to run again. Oh - I mean physically run. Stay on the line. I'm not going anywhere." A pause. "Well, technically I am. I'm running. But you get the point."

"Ah. Being chased?"

"Just because you un-hacked my omni-tool doesn't mean I can suddenly tell you mission details," Padok pointed out. "Which - thanks for that, by the way. Clever trick, spelling out the question - I almost didn't catch it, but those sentences sounded… off. I'd almost forgotten that code. Thanks for noticing."

"No trouble." He leaned forward further onto the table, then questioned, "Who hacked you?"

"Can't say that either. They cracked my omni-tool's defenses as soon as I landed, though, damn it. Took the entire database access offline. Clearly there's something here they don't want me finding. Thanks for calling, by the way. I'd - well, let's just say I'd be in some trouble if you hadn't."

"Why not call reinforcements?"

"None nearby. And you're STG - or, ex-STG, and you're sometimes regarded as a bit of a crackpot - sorry, no offense - which is even better. Either way, calling someone obviously STG would have tipped them off. And when it comes to you, we may disagree on things, but - kirbhon kur."

Mordin chuckled at the 'crackpot' comment. "Fair enough."

"Hey, one more favor?"

Mordin glanced across the room as the centrifuge let out a small ding!, and he hurried forward. "Yes?"

"I can't send you a file, but I can read something out for you. Can you translate it? My translator won't do anything with it."

"Of course." Mordin clicked the test tube out of the centrifuge and quickly began separating the resulting substances. "Phrase?"

"Uh - it looks like 'ladjmahk mlirterkh islak.' And it's next to a timer."

Mordin's movements stilled. "Timer?"

"I searched for an energy signature - my first thought was a bomb. But I can't find anything, so I think it's research equipment."

"Don't recognize language," Mordin mused. "Cannot be any of main languages, or translator would work."

"The great language master doesn't know the language?" The slight teasing tone of Padok's that Mordin was so used to had returned. "Really, though, you don't even recognize it?"

"Sounds vaguely like Krestnock." He shook his head. "Can you tell me about world?"

"Not much. It's pretty lush, I can tell you that - but it's also deadly. I can't be any more specific."

"Ladjmak mlirterkh islak.'" Mordin repeated the phrase. "First word sounds like Covus; does not make sense. Mlirterkh similar to Krestock - 'mlirch' is 'wire.'"

"Old Krestnock?"

"Hm." Mordin hummed. "Unsure what ladjmahk means, but mlirch - wire - and terkh - " Mordin went still, gripping the test tube tightly. "Sure about bomb?"

"Er - yes. I triple-checked, Mordin, you know I would."

"Terkh means weapon."

"Well. Okay."

"Possibly Old Krestnock - hm. 'Wire weapon.' Old Krestnock would mean old firing device - ancient," Mordin said quickly. "Would possibly show up as inert - no volatile components if buried or otherwise obstructed."

Padok cursed. "That timer's active." He paused. "I guess that may be what they didn't want me to find. Damn it, this was supposed to be recon!"

"Get off planet," Mordin said immediately, and Padok cursed again.

"I still have something I need to do here."

"Can't do it if dead," Mordin stated firmly.

"Can't do it at all if an ancient bomb goes off! I've got to go defuse it."

Mordin hesitated for a split second - torn between telling him to leave, or good luck. "Be safe," he told him sharply.

"As always." Padok hesitated. "Do you have enough info about the swarm idea?"

"May call you again. Have idea for preventing husk transformation, husk weapons. Would like to confer."

"At your disposal." Padok muttered something else over the line, and Mordin heard a thump. "Mordin, I've got to go - if this bomb is active and it goes off, it'll nullify the whole mission."

"Take care of self, too," Mordin added, and Padok huffed.

"Take your own advice, old man."

"Mm."

"I'll be careful, all right? I have done this before. You know I have."

"Mm, yes," Mordin said lightly. "Like old times."

"Not as spry, am I." He sighed. "Though, neither are you. Thanks again for hacking my hacker. I owe you."

"Call when available about husk ideas," Mordin said briskly. "Go, before timer runs down."

"I've got several hours - although if it's old, it may not be reliable." A beat of silence. "Yeah, I'd better go. Thanks again. And good luck with your project."

"Good luck with yours," Mordin replied.

"Catch you later." He hung up.

Mordin rocked back on his heels and, realizing he was still holding the test tube, set the tube down in a spare rack. Husk prevention, hm? Protease, enzymes… It felt glaringly obvious, now. An enzyme inhibitor, if he could engineer one, would hypothetically block all tissue breakdown. Even if it couldn't save a person, at least their body wouldn't be desecrated and turned against their would-be allies. He'd need a husk sample, though.

He reached out automatically to call Shepard - then hesitated. They still weren't on the best of terms - polite, but there was tension, ever since she'd bluntly taken him off active duty after what many had begun to refer to as 'the pipe incident.' He'd send her a message.

Meanwhile, though, he turned back to his lab equipment. He had tests to run.

Author's Note: I have a confession: Old Krestnock is not one of my created languages. It's a combination of variations of New Krestnock and a bit of Covus, actually. Still.

Also, fun fact: the "code" Mordin uses is the word "hacked," spelled out like an acrostic poem, but in Covus. So, if you took "Nevertheless," "guess," "extracting," "detect," "bad," and "poor," and translated each word into Covus, the first letter of each of those words in line would spell out the Covus word for "hacked," or "lahqahka." (Does that make any sense at all?)