Chapter One

Pyrophoria

"Got the new batch of donations, Alphy."

The gruff owner of the voice was already halfway across the laboratory, a massive cardboard box hoisted high on each shoulder, by the time the lab door banged shut behind her.

Dr. Alphys looked up from typing to watch the muscular figure approach; her nervous gaze flitted back and forth between the figure's lithe midsection and the boxes on their precarious perches. "C-careful with those, Undyne. There's probably glass."

"I know, I know! Give me some credit, will ya?" Arriving at the bench where the diminutive scientist was seated at her computer, Undyne in one swift and careful movement deposited the boxes on the ground with scarcely a clink of glass to be heard from inside them, then in another movement equally swift reached out to scoop up the scientist in her powerful arms. Alphys giggled helplessly, flushing bright red as her lover kissed her snout. Even after four months together, the passion that Undyne invested in her romantic gestures still took Alphys's breath away.

"H-hi," she eventually managed to get out between kisses.

"Mmmm. Whatcha working on?"

"E-mails. I'm trying to coordinate with the Queen in reaching out to human scientists who m-might be willing to help us out with supplies and equipment. We need more of...well...everything." Alphys sighed, shoulders sagging. Lately she'd been spending almost as much time leafing wistfully through scientific catalogues as she did reading manga. Sometimes Alphys missed her old laboratory, where everything was familiar and she had all the equipment she needed. After the breaching of the Barrier, Queen Toriel had been kind enough to permit her ex-Royal Scientist to return to the Underground to direct the salvaging of any useful supplies from the old lab. Alphys had taken her time on that last visit, going through the rooms that had once been home to her and running her paws over the familiar panels of the instruments that, on the Surface, would no longer be of any use.

No, not all her old instruments. The DT Extraction Machine had been demolished, at her request, before Alphys would consent to go back Underground.

Undyne, noticing her girlfriend's dejection, wrapped her webbed hands over Alphys's shoulders, massaging with her fingers. Alphys squirmed and squeaked in her chair. "Oh, Undyne…" she couldn't help but sigh.

"I knew that would make you feel better," said Undyne, resting her chin on Alphys's head. "So? Any more help on the way?"

"Maybe. There's a biochemist at Eglinton I've started talking with. He actually seems thrilled that he can talk to a real m-monster scientist!"

"A m-monster nerd you mean," said Undyne with an enormous, tooth-filled grin. "Bet the humans are surprised we even have scientists. Or nerds." She punctuated her last remark with a kiss to Alphys's cheek.

"Oh yeah," said the scientist. "But it's a way to get a conversation going. With s-some of them anyway. They're interested to find out just how much we've been able to piece together of h-human science just from what they threw away."

"Mmmm," Undyne said, half her mind on Alphys's words and the other half on her body. "Whatcha wanna work on now? Maybe we could, uh, take a break…"

"Undyne! Every h-half an hour you want to...well…" Alphys turned redder before she could get her last words out. "T-take a 'b-b-break'".

"Fuhuhu. Can you blame me?"

"N-no." Alphys swivelled her chair round to face Undyne, wrapping her arms tightly around her lover's body and gazing up at her face. "Tell you what, Undyne. Let's sort through the stuff you b-brought in and when we've got it all inventoried and put away...then we c-can...you kn-know…"

"'Take a break'," finished Undyne. "Oh, Alphy, you're still such a bashful, blushing dork and I love you for it." Reluctantly she disengaged herself from their embrace and went over to the boxes. "Just tell me what I gotta do!"

"R-remember to put a lab coat on first! And your face shield! I don't want you losing your other eye," Alphys added, shivering a little in fear at the prospect as she put on her safety glasses.

"Ngahhh, I hate this clumsy-ass shit," growled Undyne as she fumbled with the coat. "Do I even need this fucking thing? You know how tough I am? Throw some sulfuric acid at me, I dare you." She smiled her shark's smile and gestured theatrically toward her own body. "I bet it wouldn't even sting."

"UNDYNE!" The little scientist's eyes were wide with shock. "I'm not taking any chances with safety. D-do you know how...how b-bad I'd f-f-feel if something I did g-got you h-h-hurt…" Tears began to well in Alphys's eyes.

"Aw, Alphy!" Undyne rushed to back to comfort her lover, cradling her in her arms. "Sorry, hon, I forget sometimes how seriously you take all this safety stuff. I'll be careful. I promise." She reached down a fingertip to wipe away the tear.

"T-thanks, Undyne," sniffled Alphys. The lizard went back to her computer to open up their supply inventory; the fish, after one or two more muffled curses, finished buttoning her ill-fitting coat and donned her Lexan face shield. It had been impossible to find human-made goggles or glasses that Undyne could wear—her head fins got in the way of everything they tried—so they opted at last for the face shield. It was overkill but it reminded Undyne of her days in armor. Also, Alphys had to admit to herself with a frisson of guilty pleasure, she thought Undyne looked sexy in it.

"Okay! Got my nerd coat on, got my plastic windshield. Let's do this thing!" She opened up the first box she'd put down. It was part of the slow trickle of lab supplies that, through Queen Toriel's kindly diplomacy and Ambassador Frisk's uncanny facility for making friends, had started to come in as donations from a few colleges in the state. Some went to Toriel's school; the rest came to Alphys: second-hand glassware, instruments that had been replaced when they got too old, chemicals discarded from stockrooms. Undyne would make regular expeditions from the monster settlement to collect the donations; Papyrus would always chauffeur her, partly because his overflowing bonhomie endeared him to many of the humans and made them easier to deal with, partly because after four months on the Surface he was still the only monster to secure—somehow—a driver's license.

Because Undyne was so eager to help her girlfriend in her new laboratory, Alphys was teaching her how to read chemical names and identify pieces of equipment. The former soldier had protested loudly and frequently that it wouldn't be any use: "Sorry, Alphy, you know how cool I think all this nerdy stuff is that you know, but I'm never gonna be smart enough to understand any of it!" But it turned out that Undyne had an excellent memory for names and jargon, and a wide-eyed fascination with every new thing they came across that warmed Alphys's heart, reminding her of the earliest days of their friendship.

Undyne peered into the cardboard box. "Looks like all old chemicals, Alphy," she said, gingerly lifting out one dusty bottle.

"OK. Read out the name of each one to me, Undyne, and tell me how empty the bottle is. Oh, and tell me what the stuff looks like, just a short d-description. Look inside if the bottle's opaque. Then I'll tell you if you should sh-shelve it or not."

"Gotcha." She read the label on the bottle she'd just pulled out. "Uh…'nickel(II) chloride hexahydrate'," said Undyne, carefully stepping over each syllable. "Bottle says one hundred grams." She opened it up. "Oooh, look! It's bright green! Clumpy green crystals. Maybe half-full."

Alphys smiled and keyed in the information. "Put that one with the regular chemicals."

Undyne deposited the nickel chloride bottle on the appropriate shelf in the laboratory's chemical storage—still far too empty, thought Alphys—and returned to read a second. "'Calcium chloride, anhydrous'. Supposed to be two hundred and fifty grams." She scrunched up her face as she peered into the bottle. "Looks like half of it's dissolved or something, it's all liquidy."

"Crap. Means it's d-deliquesced. Uh, I m-mean, soaked up water from the air. Put it on the bench, we'll figure out what to do with it later."

"Right. Okay, next one." Undyne peered at the brown glass bottle and its decaying label. "Huh, good long name. 'Lithium aluminum…'" She stumbled a little on the last word. "'Hydride', is that how you say that?"

"Lithium aluminum hydride?" Alphys's mouth fell open. "What's that doing in there?! Undyne, don't touch that one—"

"Huh? Why not?" Undyne gave the bottle's cap a testing squeeze. There was a popping noise, the cap fell to the ground in two pieces, and a spurt of brilliant red flame issued from the open mouth.

"FUCK!" Undyne hollered, shocked but not flinching or dropping the bottle. Alphys leapt up from her chair with a scream.

"Don't worry, Alphy, I got this!" Undyne leapt for the nearest sink.

"NOOO! UNDYNE STOP—"

With a warrior's speed and grace Undyne reached the sink in a single bound, dropped the flaming bottle in the basin with one hand while wrenching the cold tap open to full with the other. With an angry hissing noise and then a loud crack, the bottle shattered and a ball of red fire and sparks erupted from the sink. "NGAHHHHH!" Undyne bellowed, stumbling backward from the flames rolling toward her.

Into Alphys's head flashed nightmare images—dripping, melting bodies, bubbling cries for help, outstretched limbs collapsing into pulp. She screamed again and made her own leap, straight at Undyne, wrapping her arms about her torso and hurling her to the ground as the flames bloomed toward the ceiling. Scrabbling to her feet Alphys locked her paws onto Undyne's smoking lab coat and dragged her toward the far corner of the room.

"Alphy?! What are you doing? I'm fine—"

"Shut up! We need to get you to the safety shower!"

The scientist's commanding tone startled Undyne into compliance, and she said nothing more as Alphys reached the shower, pushed her girlfriend under it and yanked the handle. Undyne spluttered at first when the cold water hit her, but soon she was relaxing under the stream, fluttering her fins. She tossed the face shield gently to the floor and began undoing her scorched coat. "Mmmm, Alphy, this water is actually kind of nice."

"Sh-shut up," Alphys said again, but in a tearful murmur as she collapsed against Undyne, letting the water cascade over her as she clutched her lover's waist and wept into her chest.

"Alphy…" Undyne wrapped her hands around Alphys's head, petting her gently. "What's wrong? Why are you taking this so hard? You'd think this was the first fire I ever started in here."

"It's n-not," said Alphys into Undyne's chest. "B-b-but it's the f-first where I th-thought you'd b-be hurt…"

"A little explosion in my face isn't gonna hurt me, Alphy! I blew my own house up making spaghetti, remember?"

"That was d-different. Th-this time...it w-would've been m-my fault. If I h-hadn't t-t-told you to l-look in the b-bottles…" Alphys started crying again.

Undyne knelt, cradling her lover's head against her shoulder. She's still so fragile, Undyne thought. "It's not your fault. Shhhh. Shhhh. You haven't hurt me, Alphy. I'm not even singed. Shhhhhh." They held each other there under the flowing water until Alphys's tears stopped and her body relaxed in Undyne's arms. "There. Do you feel better now?"

"Y-yes." Alphys looked up into Undyne's face and ventured a tentative smile. "You're s-so strong. N-nothing frightens you. I wish I were like that."

"Whoa there! Don't sell yourself short! You fuckin' rocked with that tackle move of yours. Alphy, look into my eyes." She took the scientist's paws in her hands. "You knew exactly what to do to help me and you didn't waste a second doing it. Don't tell me that's not brave and strong." Undyne kissed her. Alphys blushed and cooed with pleasure.

"That's my smart little lizard. Now…" Undyne hauled herself and Alphys to their feet, out from under the still-flowing shower. She pulled on the handle a few times but the water still rained down. "How do you turn this fucking thing off?"

"It's a d-different valve." Alphys twisted the shut-off valve closed. They both looked toward the sink where the trouble had started, halfway expecting a raging inferno, but were surprised at how little had happened. White ash covered everything within a few feet of the sink and the bottles of soap and wash water had slumped in the heat but otherwise the lab looked intact. Alphys sighed in relief.

"It must have b-burnt out quickly, once all the lithium aluminum hydride had reacted. The bottle m-must not have had much in it."

"What the fuck kind of crazy shit catches fire under water?! Actually, that's pretty cool." Undyne giggled, then frowned. "I wish I'd known ahead of time though. You knew. I told you, Alphy, I'm too dumb for this stuff."

"You're not dumb! You just need to learn more."

"Okay, if you say so. For now though, Alphy, put me on the simpler jobs, huh? Like maybe cleaning up this fuckin' mess." She groaned and looked around, trying to remember where they'd stashed the mops, but then came the welcome sensation of an arm curling around her waist and a paw reaching underneath the front of her sodden shirt to stroke her scaly belly. She looked down to see Alphys, smiling, with a familiar glint in her eye.

"First things first. As good as you look in a wet T-shirt, Undyne, I think m-maybe we should get out of our soaking clothes."

"Time for a break?"

"Ohhh, yes."