Erina and Akira settled into their rooms for the night. Lazarus, it turned out, could generate a spare change of clothes as easily as food and drink. They spent the evening catching up—Lazarus had spent the last several years in this bunker. Originally, it was barely more than a few rooms, an emergency hideout set aside decades ago with the barest essentials. She'd spent the years slowly amassing materials, tinkering with what she had, and mining into the earth with what she called the "Finger" for resources until she had enough to create a second isolated space and accelerate her work from there. It wasn't anything close to even the old lab, but it was plenty comfortable in its own right.

  "Speaking of the old lab," said Akira as they sat in front of the fireplace, "any objections? The boys and I have been gettin' our fingers all up in it and all."

  "If Erina is with you," said Lazarus, "I imagine you wouldn't put it to any use I'd object to."

  "Then, it's my responsibility now?" said Erina.

  "Hasn't it been for some time? Let's just say this makes it official!"

  "Um, I see. Thank you. I'll do my best…"

  It really was comfortable. There was a room full of nature and sunlight available, plenty to explore and work on, and there was always room to build new units, start new projects. Erina could see how quickly time could vanish in the midst of them all. It made her wonder how many decades, maybe even centuries, had gone into the first laboratory.

  Before she knew it, several days had passed. Some time later, Erina found herself wandering the halls on her own, getting a feel for the layout and peeking into each room as she passed by. The laboratory had the same familiar feeling as the one she woke up in. She knew the corridors were comprised entirely of those articulated panels. Likely, the entire bunker could rearrange itself at will to suit its owner's desires.

  She strolled through each of the rooms she came across, fingers brushing along the surfaces of the machines. It was rather like introducing herself to each of them, and they introduced themselves to her in turn. Lazarus used these instruments every day, whether it was for research, housekeeping, or plain entertainment. Erina felt like she was meeting her mother's friends and colleagues.

  She poked around the hospital wing. It had all the amenities and equipment for regular checkups, patient care, surgery, and then some. A particularly menacing machine sat in the corner, hidden by a curtain and covered with arms that ended in all sorts of surgical and mechanical tools. Erina eventually identified it as a maintenance unit. Had Lazarus ever used this on her? It still seemed to be in pristine condition. She knew her mother would have the common decency to put her under, but… it still looked more like a torture device than a tool meant for conducting maintenance on a living person.

  A few cute disk-shaped cleaning robots passed her down the hall, on their ever-busy way to dust the floor and keep the space tidy. Erina had all sorts of questions to ask her mother about the lab and these new and familiar but different devices she saw.

  "Mom?" she said. "Can I have a moment of your time? …Mom?"

  Lazarus didn't respond.

  Erina turned on the spot a few times. All she had to do was speak up, right? "Mom, are you there?"

  She spotted a speaker mounted on the ceiling and walked over to it. She got onto the tips of her toes and strained, but couldn't quite reach it even with the tips of her fingers. Wait, what was she doing?

  Erina stepped up on a few elevated spell circles and touched the speaker. Fully functional. No issues. So what was going on?

  The lights flickered.

  Erina blinked. Imperceptibly, something changed. The laboratory didn't feel quite like it did a moment ago. "Mom?"

  Her butterfly clip twitched.

  Erina touched two fingers to it. She felt a pulse of mana.

  "Erina!" Lazarus' voice crackled through as the communication spell triggered. "—hear me? There's—"

  "Mom," said Erina. "I was trying to call you. What is it?"

  "Can you hear me?" The audio suddenly came into sharp quality. "Erina, the distortion field is compromised!"

  "What?"

  "The bunker's exposed! I've never seen anything like this before. Almost all the systems are down, I could barely get basic heuristics running again—there's two signals coming your way!"

  Erina's heart picked up the pace.

  "Erina, we have intruders! The—"

  A harsh sound came across the connection, and then Akira's voice cut through loud and clear.

  "Erina, get the fuck out of there NOW!"

  Crimson red filled Erina's vision. A hundred scarlet arcs tore through the air in front of her, flooding her view. They were gone by the time she flinched back, leaving countless thin lines in the metal of the corridor. Then—

  The wall exploded. Thick dust and fragments of metal sprayed into the corridor. Erina staggered away from the suffocating cloud of black, green katana flashing into her grip as she threw an array of orbs into the air behind her.

  She felt a shift in the stream of mana linking her to her allies. The connection was cut.

  The smoke began to clear. Rays of sunlight streamed through the hole in the wall. The bunker was no longer safely nestled in its own pocket dimension, but dragged into the open in the Reverse.

  She heard footsteps. Erina readied herself.

  Dark metallic greaves crunched through the rubble and stopped in the middle of the hall. They were joined by a pair of leather boots, an immaculate gilded white coat flowing in their wake.

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  A clenched fist opened. Markings of black lightning faded. The laboratory shuddered back to life with the invisible chokehold released. Red lights flashed through the hallways and klaxons blared as the alarms activated all too late.

  Erina's heart crept into her throat. Pins and needles prickled her back as a clammy sweat began to break out. They couldn't be here. Why the hell were they here?!

  "Breach successful." Asayuki raised one hand to her winged headpiece. "Mission control, come in."

  "I read you." Julian's grainy voice came through the receiver. "Void space status?"

  "Dimensional collapse confirmed." Darius stood back to back with his partner, idly twirling his revolver in his left hand. "Exposure is twenty percent."

  "It's sufficient. Topology verified. Beginning full scan. Secure the area and proceed as planned."

  "Roger!" they said in unison.

  A bright light shone from Darius' figure. The air cracked with an echoing boom, and then he was gone, leaving nothing in his place but a streak burned into Erina's vision.

  Asayuki settled into facing the opposite direction her partner went, towards Erina. Icy blue eyes met bright green.

  Erina's feet moved back before she had the chance to stop them. She willed herself not to retreat any further and moved for her blade, ready to draw at any moment as spell circles glowed to life at her feet. She already knew talking was pointless.

  Asayuki's black visor locked into place and she advanced on her quarry.

  The cloud of orbs at Erina's back opened fire. The red of the alarms gave way to bright green. Erina's color flooded the corridor, only to meet the crimson vortex that was Asayuki's blade. Dozens of slashes tore at the air, blocking and neutralizing shots as dozens more hammered into the hall around the swordmaster. Before Erina knew it, Asayuki was upon her.

  The blistering quick draw smashed and grinded against Erina's rune circle barrier. The layers ripped apart as fast as they multiplied. Erina broke away as it shattered, fragments lingering in the air between them as she staggered back.

  Another flash of crimson. Erina's next barrier broke too, the girl herself flung back from the arcs of red filling the air.

  "Another encounter, another application," muttered Asayuki. The magic-killing blade returned to its sheath, ready to draw with explosive power. "Julian was right."

  "What?" said Erina.

  Asayuki ignored the question. Erina backed off further as her enemy stepped forward, klaxons blaring and disorienting red alarms assaulting her sight. The swordmaster crouched closer to the ground, energy coiling, and Erina braced herself for the next storm.

  The hallway went red, the klaxons blared, and this time, the laboratory itself burst to life. The lights turned blue and the floor broke apart, articulated panels rising up to form a solid barrier between hunter and hunted. Another wave of panels rose up for every step Erina took back, blocking the way as Asayuki slashed and hacked at every obstacle in her path.

  "Erina!" Lazarus' voice came through, emanating from her daughter's butterfly clip. "I'll keep her occupied!"

  "Mom!" said Erina. "Are you okay?"

  "For now. You fall back and regroup with us!"

  A burst of mana and Erina jumped as a vast crescent arc tore through the corridor. Every panel between them flew away, torn in half. Twin gashes tore through the walls on either side. Despite being over a dozen yards away, the arc only barely stopped short from cutting down Erina where she stood.

  As the rubble and broken metal parts fell, Erina could tell Asayuki was looking directly at her under that black visor.

  The swordmaster leapt—

  The torn walls slammed shut on huge robotic limbs, glowing red ether spraying as the walls crashed together with Asayuki between them. Several panels around Erina opened up, blue eyes watching the enemy alongside her as the walls shifted and kicked Asayuki back where she came. The walls split apart next and separated into smaller panels, twisting and rotating their parts to bring the concealed laser turrets to bear. Asayuki unsheathed her blade proper and settled with it at the ready before her.

  "What are you doing?" said Lazarus. "Now's your chance!"

  Erina jolted back to awareness as the turrets opened fire. She tore her eyes off the battle and fled down the hallway. The sound of ringing steel, consecutive explosions, and high-pitched lasers echoed after her amidst the resounding alarms.

  "Where are you?" said Erina as she ran.

  "Don't worry about that!" The ground shook. "I'm moving the units around as we speak. Just put more distance between you and her. I'll come pick y—"

  An unseen force swept through the laboratory—immaterial, invisible, but all too real. The tremors came to an abrupt stop. The greatest Affinity in the world asserted itself.

  "What happened?" said Erina.

  "Darius!" said Lazarus. "Looks like he remembered the last time we met… Erina, the laboratory stopped in the middle of rearrangement! The engine room is isolated in void space, you need to—"

  A pattering of footsteps behind her. All of Erina's instincts told her to dive and she did without question.

  Asayuki's sword cut a tall vertical gash into the wall as Erina rolled away, the green katana forming in the nick of time to repel the follow-up. Erina and Asayuki had each other one blade's length apart, several spell circles at the former's feet to call on the techniques she needed to defend herself.

  "Erina, are you okay?!" said Lazarus.

  Asayuki flashed back several paces in the blink of an eye, red afterimages trailing her movement. Her katana returned to its scabbard.

  Before Erina could act, Asayuki drew and sheathed again, and Lazarus went silent. Erina didn't even see more than a few inches of the blade leave the scabbard. Imbued with the power to destroy all forms of magic, Asayuki's blade severed the connection.

  A flock of ethereal butterflies took flight and Erina backed up, throwing a field of Menger sponges into the space between them. Asayuki was a blur of motion, crimson sword lashing out again and again at the barrage of lasers showering down on her. Erina's spear met the ground next, twisting the metal forwards and outwards into a thick tangle that melded with the minefield. Her Menger sponges lay hidden away in the branches, turning every cut Asayuki made into a potential backfire if they exploded on her. The butterflies remained small enough to weave through the tangles, firing down on Asayuki while she was denied a clean path to Erina.

  Erina didn't expect it to buy her more than a few seconds.

  Corridors were dangerous. Erina couldn't afford to fight in an enclosed space like this. The spear formed in her grip and Erina rammed it into the wall beside her, blowing it apart with the branches of lighting. Her butterfly clip glowed to life and she leapt into the dark beyond.

  Erina landed on the roof of a large room. She could see the hallways and rooms around her in the darkness, all suspended by unseen great chains in this void. She could also see the gaping hole in the black, hazy sunlight streaming in from the outer world of the Reverse. That was the rift where Asayuki and Darius had punched clean through the pocket dimension to force their entry.

  Erina flicked one orb into the air that multiplied into a floating cloud. The butterflies took flight, vibrant against the dark as they fluttered around her. Erina flung one spear after another into the floor around her, each one compacting into a tiny glowing point on the metal.

  She raised her hand and flourished. Three arrays of spell circles formed overhead. Streams of orbs descended from the cloud, compressing together into shining balls of light ready to be loaded into their chambers. Erina could feel the sweat on the back of her neck. She exhaled and summoned her katana into her grip, memorized techniques engraved into the seals at her feet. Erina spared no expense. Everything she could think to prepare, she did.

  A series of chain explosions and then Asayuki leapt free of the corridor to land alongside Erina. She straightened up, head turning slightly to acknowledge the situation she had jumped into.

  "Status," she said. "I have Emisane."

  "Topology disrupted," reported Julian. "Scan restarted, now at twenty percent."

  "Darius, come in. What's your status?"

  "Engaging Akira," said the gunslinger over the connection. "Lazarus is unaccounted for, but she won't leave. Are we on 'business' today?"

  "Seal release authorized at your discretion," said Julian. "Go at your own pace. I'm sure it's enough."

  "Oh, you can bet on that."

  "Proceed as planned, you two."

  "Understood." Asayuki's gaze settled on Erina. "Resuming combat. Out."