Part Three - Resolution

Chapter Ten - Key

...

Toushiro found himself deep in Mayuri's files. The white light from the giant computer reflected off his face in the otherwise darkened room. A few lamps flickered behind him, but their light was dulled by the glow from the monitor. Toushiro found the cross between modern technology and the Soul Society's archaic time period amusing. He chuckled at the fact that there were open-flame lamps in the same room as a computer. Yet, it was fitting for such a place as the Twelfth Division.

Kurotsuchi was the inventor of a number of utilities, including quite a few things to do with the Underground Prison. He had invented the seals that bound Aizen during his imprisonment in Muken. If the captain wasn't so abrasive or if he had shown Toushiro even a modicum of respect then he would have been impressed at his achievements. Right now, however, he was annoyed. Kurotsuchi had purposefully hidden this information from him; he had still found it, but the fact that he was acting paranoid, like Toushiro wanted to steal his research for himself, made him wonder if Kurotsuchi really wanted him to succeed.

Kurostsuchi is a bastard, Hyourinmaru growled, even when he's helping, he's a bastard.

Toushiro chuckled softly as he examined the files. Kurotsuchi's data was hard to understand at best; he seemed to work in an arbitrary system of numbers and a unit of measurement that Toushiro had never heard of. Though, he had never even heard of someone using a unit to measure reiatsu. He ground his teeth at Kurotsuchi's inventiveness. The Gotei Thirteen should be using this system of measurement; right now all they had was a comparative system based on whether or not a person had achieved bankai or not.

According to Kurotsuchi's system, a captain had at least 85u of reiatsu, and for a soul to be a shinigami they needed at least 15u. Toushiro tilted his head, wondering briefly how much he had or how reiatsu was even measured. What equipment did Kurotsuchi use? He shook his head and continued to read. Azien's reiatsu seemed to be somewhat of an anomaly. He kept so much of it hidden that Kurotsuchi had come up with an equation to measure it. Then there was the fact that he used the hyogyoku to amplify his powers and that called for another variable to be worked in. Toushiro considered himself to be smart, everyone called him a genius – a prodigy, but the calculations that Kurotsuchi had produced were making his head spin. Given enough time, he was sure that he could decipher the mathematics behind it, but now he was more interested in the results rather than the process. Kurotsuchi had estimated Aizen's reiatsu to be approximately 190u. Toushiro swallowed thickly; 190 was a large jump from 85.

So how strong is Kurosaki? Hyourinmaru asked in awe.

Toushiro shook his head and he felt his stomach start to sink. No wonder Aizen had struck him down so easily. He was so ridiculously strong that he never had a fighting chance against him.

Hyourinmaru growled in warning, causing Tosuhiro to chew his bottom lip as he refocused on the report.

In order to seal Aizen, Kurotsuchi had come up with a different formula that accounted for Aizen's power increasing. The seals worked in such a way that they compressed the wearer's reiatsu to their body. They didn't eliminate the reiatsu but rather contained it. Therefore, it was impossible for them to affect any of their surroundings while sealed. Since Aizen's reiatsu was measured at 190u the seals were designed to hold twice that amount. Kurotsuchi had also made calculations to include exponential growth, so if Aizen's reiatsu grew at such a rate the seals would counter balance it with their own restrictions. Despite Toushiro's distaste for the scientist, he couldn't deny that he was impressed. Kurotsuchi's research was nothing if not thorough and inventive.

He closed the file for a second and then closed his eyes. He hadn't realised just how deep this research went. So much was put into imprisoning Aizen, so how had Momo slipped past it all? Now he wasn't even concerned with how she had gotten in to Muken, but how she had gotten Aizen out of those seals. And if she had, then it meant fresh hell for all of the Soul Society. Just what exactly had he unleashed? If he had just pushed his emotions back, like he was supposed to do, then he could have stopped Momo before she did any of this. Now more than 190u of reiatsu was free and they had no hope of imprisoning him again. His thigh twinged and he rubbed at it in annoyance.

Hyourinmaru huffed, None of that now, little one, we still have much to figure out. I'm sure that Kurotsuchi has the details of Aizen's escape somewhere here. We need to find out more about those seals. If Momo broke them somehow, then...

Toushiro sighed heavily. Hyourinmaru was right, he always was; self-pity wouldn't get him anywhere right now. He dug a bit deeper into Kurotsuchi's personal files, making sure to keep his senses alert so the scientist could not seek up on him. The computer screen went blank for a while and Toushiro prayed to the soul king that it wouldn't ask him for a password. He breathed a sigh of relief when he clicked the folder open and pulled up a few of the documents that were inside. He couldn't begin to understand the process of building the seals, or the calculations that went into them, but he did find out that they could be released by a corresponding key. Momo could have gotten her hands on these keys somehow, even though he was sure that they were guarded... possibly in the Central Forty-six's chambers or even with the guards of the Underground Prison.

He needed to do way more research on the Underground Prison itself, in that case. He grumbled in frustration; that's what Kurotsuchi had meant when he said that he needed to do more. The fact that Kurotsuchi had been right was bitterer than the fact that he hadn't tried hard enough.

Toushiro was doubtful that details of Aizen's escape would be held in the archives. More than likely, only the Central Forty-six or the prison guards would be privy to this information. So he idly clicked through a few files, wondering how he would go about finding what he needed. He didn't think that Kurotsuchi would help if he asked, and he would rather not ask. So, he was shocked when he discovered a file dedicated to stenographers reports for all the criminal trials that were held over the past thousand years. Toushiro felt his breath leave his lungs as he clicked through the reports. Surely, this information wasn't supposed to be in the main archive, where anyone could access it. He really shouldn't underestimate Kurotsuchi's ability to snoop around and collect information. His spine itched at the thought of all the dirt the scientist had possibly collected on him – he considered everyone to be a test subject after all.

Toushiro ended up printing a hard copy of Aizen's trial and hiding it in his sleeves when he left the Twelfth for the night. There was still so much to do, to research, if he truly wanted to get to the bottom of Momo's involvement. From what he had learnt so far there was no way that she could have released Aizen. The seals could be broken with enough reiatsu, but if Aizen couldn't break them, then it would be beyond impossible for Momo to. He needed to look into the whereabouts of the keys next.

Toushiro wished that his leg would allow him to use shunpo. He was eager to get back to his office and piece together pieces of this puzzle without the threat of Kurotsuchi looming over his shoulder. Seals aside, Momo had to have had outside help. The more he had learnt about Muken and the security, the more he firmly believed that there was no possible way for Momo to have done everything by herself. But if she had been working with someone, then who was it?

The thought made his stomach bubble with trepidation. It would have had to be the same person who had turned his men into hollows. He could not guess their motive for doing so, but they seemed to be related to Aizen closely enough to want to release him. Toushiro chewed the inside of his cheek and scowled at the flagstone-covered ground. As far as he knew Aizen's disciples – Tousen and, he hesitated to say Ichimaru, but the man had played the part of a double agent magnificently – were dead. It could have been one of his arrancar minions, however. Toushiro wasn't sure of the whereabouts of each of the espada. But, if any one of them was still loyal to Aizen then it could be possible for them to have helped Momo. Besides, who said that it had to be one of them? Aizen had had ten espada at his service, majority of them had been defeated, but there were a few that still roamed about.

Toushiro swallowed against the nausea that rose upon thinking about how difficult it had been for him to defeat the espada,Tia Harribel. His leg spasmed and he nearly stumbled. He caught himself before he tumbled over by jamming his crutch into his armpit, but that in turn sent a jolt down his left arm. He swore softly. If it was the espada behind this, and mixed with Aizen freed of his bonds, then he truly had no hope against them. A bitter taste spread from the back of this throat to the rest of his mouth and he noticed that his heart was beating frantically. What exactly had he gotten himself into?

...

"Captain, did you sleep at all last night?" Rangiku asked, bending over him as he slumped across the top of his desk.

Toushiro rubbed his eyes with his palms and slowly sat up, ignoring the crick in his lower back. He had fallen asleep at his desk again; Unohana would not be pleased to hear that.

Rangiku sighed, "I'll make you some tea."

By the time she came back with a cup full of steaming, green tea he had managed to wake himself fully. The tea was a relief against the stale taste in his mouth, but he had to stand up and stretch to work a bit of feeling back into his limbs.

"You slept at your desk, didn't you?" Ragiku asked with a sigh.

Not choosing to answer was answer enough.

She shook her head. "Captain, I don't understand. What is so important that you need to sacrifice your health for?"

Toushiro hesitated. He sat back down before answering. "I was... I might have found out some key information as to why Hinamori came back that night."

Rangiku raised her eyebrows. "Really? How?"

"I still haven't nailed down a specific theory yet, but Kurotsuchi had some useful information in his – the main archives."

"You went to Kurotsuchi?"

Toushiro rolled his eyes. Was he so childish that he'd let a grudge get in his way? "He had information, so yes."

Rangiku hummed, "So, any leads?"

Toushiro hesitated; he was dealing with a tricky subject matter here. It would be best if Rangiku wasn't completely involved. If things turned bad then he could take the fall and not have to include her in his mess. "A few. Nothing solid, however."

When it became clear that he wasn't going to say anymore, she tucked a lock of hair behind her ear and ambled over to her desk where she picked up a sheet of paper. "What's on the agenda for today?"

"You can handle the paperwork for all the new clubs-"

"Captain-"

"I just need a finalised list of members and budget estimates. Then you're free."

She narrowed her eyes. "What are you going to do?"

He sighed softly, "I have more research to attend to." He finished the rest of his tea in three large gulps; it had cooled enough so that it didn't scald his throat. "Don't burn down the office while I'm gone."

...

Toushiro grumbled as his thigh seized while he was swinging his leg back and forth under the table. He reached down and roughly rubbed it. He hadn't done his exercises last night, in fact... he paused. Shit. He was supposed to have met with Unohana earlier that afternoon. He took a deep breath and shut his eyes; this was not going to go well for him. He was surprised that the healer hadn't sent a rabid hell butterfly his way. He'd explain what happened when next he saw her... and send a quick message before then.

He glanced back to his copy of the stenographers report; it shouldn't take much longer to wrap up here. He had found out that the keys to Aizen's seals were kept in the Central Forty-six chambers. And, going by Kurotsuchi's files, a report on them being stolen had never been filed.

It's safe to assume that Aizen is still sealed in this case, Hyourinmaru noted.

Or Hinamori figured out a way to break them.

Somehow I think that's not so, even if she does have an accomplice. If the seals were already broken why would she return? It's plausible that she came back for the keys.

Toushiro sighed heavily. I wonder if she knows any of this information; how much reiatsu is needed to break the seals, or even where the keys are located. She should have gone directly to the Central Forty-six chambers, but instead she was lurking around the Tenth. Is she really after the keys?

It's our best bet to assume so.

So what do we do now? Do we go after the keys ourselves?

Hyourinmaru rumbled in thought. Maybe we should investigate Muken just to be sure. Kurotsuchi said that if the seals were forcibly broken then there would be visible signs, right?

Something akin to scorch marks, or remnants of an explosion in the direct area. I couldn't find anything about Muken's current condition, though.

So let's start there.

What? Break into Muken?

No one else is investigating the seals. I don't want to leave this to chance, little one. What if Momo's goal is the keys, and we figure it out too late? We don't, we won't, have another chance if Aizen is unsealed. Kurosaki was our last trump card; we don't have another one of him. And I would like to prevent another battle at all costs.

Toushiro sighed, Yes, I understand, but you want me to break into the Underground Prison. If I get caught-

Then don't.

Easier said than done.

Hyourinmaru had full confidence in Toushiro's abilities, it seemed, but Toushiro wasn't too sure if he believed in himself. Besides there was no way that he could sneak into Muken undetected. It wasn't as if he had access to... He deflated and stacked his papers into a neat pile. He was going to owe Kurotsuchi a lot after this; surely the mad scientist was keeping a tab.

...

Kurotsuchi agreed to bring him into Muken, surprisingly after very little argument. He said he had something to investigate in the Underground Prison as well, something that Toushiro's research had brought to light, and warned him, under penalty of near death and torture, that he was not to get in his way. But, he had also been impressed that Toushiro had come to a reasonable conclusion in such a short period of time. (And said that Toushiro wasn't as hopeless as he originally thought.)Toushiro, therefore, assumed that he was being rewarded by this somewhat civil attitude.

Kurotsuchi had literal backdoors to sneak into the Underground Prison. Even though he had been contained in the Maggot's Nest in the Second Division's Underground Detention Unit, it seemed that he knew his way around Muken and the other prison levels as well. Toushiro didn't ask how. Mayuri had also coated him in a slimy mist that acted as a reiatsu suppressant, which rendered him undetectable. And despite the fact that Toushiro couldn't use shunpo because of his leg, Kurotsuchi grabbed him roughly by his upper arm and shunpoed away regardless. It was all Toushiro could do to not to drop his crutch and try to keep up, ignoring the way his leg trembled and flared with pain every time they landed.

The entrance to the Underground Prison was guarded by six burly shinigami with veiled faces and long, mace-like zanpakuto. Kurotsuchi observed them for a few minutes before dragging Toushiro down a pathway, overgrown with weeds and made uneven by stones and rubble, which lead in the exact opposite direction. They walked in silence for at least twenty minutes, taking many unexpected turns and seeming to double back a few times; all the while becoming less and less distinct. Eventually, they arrive at a cracked, stone wall where Kurotsuchi wormed himself into a crevasse without explanation. They had to turn sideways to move along the rough, descending, pitch black passage. All Toushiro could hear was his own breathing and the shuffling of their waraji on the uneven ground. The passage then opened into a wider cavern; Toushiro could only tell because his back was no longer pressed against hard stone, but then Kurotsuchi grabbed his arm again and shunpoed so many times that he lost all sense of direction. When he felt his feet touch solid ground, however, they were in a dimly lit corridor. Torches hung along the hallway, flames flickering as Kurotsuchi dragged Toushiro past. A few times they escaped detection by ducking around corners when guards patrolled the corridor. Toushiro understood why Kurotsuchi had such a tight grip on his arm when he was wordlessly yanked this direction and that; he wouldn't put it past the other captain to have memorised the guards' patrol schedule. After what seemed like two hours spent navigating corridors they stopped outside a behemoth, metal door. Toushiro could tell that it was supposed to have been bolted shut – sealed – but, he assumed, with Aizen gone, there were no other prisoners housed in Muken. From the amount of patrols they had encountered, the guards were still on high alert, however.

Kurotsuchi nodded towards the door. "Do whatever you have to do and don't let the guards see you. I'll meet you back here in thirty minutes; make sure you're done by then."

"Where are you going?" Toushiro hissed, not quite sure that he wanted to be left alone in such a place, even if his company was Kurotsuchi. At least the man knew what he was doing down here.

"I told you, there is something else I need to investigate. You wanted me to bring you to Muken and I did. Stop snivelling like a baby or I will call the guards."

Toushiro scowled, but said nothing else as the other captain glided away. He then swallowed and limped through the door. The light form the torches in the hallway didn't quite reach into the vast cavern. He blinked into the darkness, unable to see where the floor ended and walls began. He knew that it was empty, and yet the great darkness and heavy silence seemed hostile. He stepped further away from the door; the light, wooden thuds from his crutch didn't even echo and he wondered if it would be the same case if he spoke.

I would go crazy if I was imprisoned in here, Hyourinmaru noted as Toushiro kicked a loose stone. How are we supposed to look for signs if we can't see anything? I don't think kido will work in here...

Toushiro tilted he head. He could take a torch from the hallway, but that might alert the guards if they noticed it missing. He'd have to be very precise. The patrols occurred once every twenty minutes – he counted on their way in. It had been around six minutes since he and Kurotsuchi had run into the last one, so if he acted now that left him with fourteen minutes to search Muken for signs of the broken seals, return the torch, and find a suitable hiding place. It would be cutting it close, but he could do it. He clenched his jaw tightly as he limped back outside and hefted the nearest torch from its bracket. The light from the small flame flickered against the shadows, fighting to shed light, but the darkness was determined not to be washed away. Toushiro could only see three feet or so in each direction. His own shadow stretched gruesomely away from him; a three legged beast that waged war against his wavering torch. He stepped further into the darkness, a prickly feeling ran along his spine, sweat gathered on his back, brow, and armpits, while his stomach warned him not to go any further. The darkness pushed down on him, suffocating, consuming, and he nearly staggered.

Hyourinmaru sniffed. It's all in your head, little one, there's nothing else in here.

Toushiro nodded, feeling the sweat drip down his back – it didn't even evaporate in the heavy, musty air, just as the door swung shut with a deafening bang. He almost fell over in his haste to turn around and Hyourinmaru growled loudly. He turned just in time to see the hairline cracks between the door and the wall glow briefly with ghostly, white light. Toushiro swallowed thickly and his stomach sank to his feet. Cold dread seeped into his limbs, numbing his fingers and toes, and he nearly dropped the torch as he hobbled as quickly as he could back to the door.

No! Nononononono, he muttered frantically.

Hyourinmaru growled softly, We're sealed in.

Toushiro swore loudly. Was it a trap all along? Kurotsuchi was planning this! That's why he left, that's why he – I'll kill the bastard! I'll –

Toushiro...

The small shinigami was shaking in equal parts rage and fear. He slumped against the door, breathing heavily. He scrabbled against the metal with his free hand, his fingernails pulling away from their beds as flakes of rust drove themselves under his nails and coated his palm.

What's going to happen to us? He whispered, brokenly.

The dragon sighed loudly, I'm not-

"Shiro?"

Toushiro froze. He stopped breathing and this time the torch did clatter to the floor. The flame was snuffed out almost instantly, but he didn't need to see to recognise the voice.

"I was hoping that you'd come looking for me."

He bit his bottom lip hard enough to taste blood and slowly, ever so slowly, he glanced over his shoulder into the darkness.

"Hinamori?"

His throat was suddenly dry and he was shaking so violently that his crutch almost slipped out from his armpit. Bile rose at the back of his throat and he suddenly felt dizzy, so dizzy. He wished he could see Momo, even if just for confirmation that it was really her. What expression was she wearing? Was she even guilty for what she had done? He turned back around and took a step forward. He bumped into a thin, warm body. Every single muscle in his body tensed with enough force to cramp as she wrapped her arms around his neck and gently pulled him into a hug.

"I'm sorry for what I did to you," she whispered into his ear.

He could feel the moisture from her breath on his ear and he swallowed deeply, both wanting to push her away and return her embrace. She felt the same; virtually no different from the countless times she'd hugged him before. He wanted to sink into her arms and welcome her back. But there was a new edge to her, a stiffness in her poise and a sharpness in her breath. He could feel it in her reiatsu too, something dangerous, untested, fiery, and explosive. Something that was not the Momo he knew.

"Yo-you're sorry?" he croaked.

He felt her nod. "I should have told you what was happening, what Aizen and I were planning."

He found the strength to push her away then. He stared into the darkness, only just able to make out her face, but he felt as if the ceiling was caving in. His legs were ready to give out, Muken was spinning around him; he couldn't even tell up from down. His heart was racing and simultaneously he couldn't find the strength to breathe.

Hyourinmaru roared.

Toushiro predicted Momo's next sentence. "I should have asked you to join us," she said and placed a hand on his shoulder. He jerked as though she had touched him with a hot coal and before he knew what he was doing he had draw his zanpakuto and swung at her neck.

Momo jumped back, seemingly unphased, as if she had predicted his attack. Then she hummed softly as she drew her own zanpakuto.

"Snap, Tobiume," she murmured lazily. The explosion that followed was the largest that Toushiro had ever seen.

...

"What was that?"

"A trap, old friend, and one that you fell into spectacularly."

A pair of eyes was narrowed dangerously. "Yo- you played with her!"

"Isn't that the point of our game?"

"No! We manipulate! We twist indirectly! You aren't supposed to openly interfere; we will be found out!"

"And suddenly you're a stickler for the rules? I don't recall you playing so fairly during our last round."

"I never increased anyone's reiatsu. I never twisted someone's free will so much that they didn't even know the reason for their own actions!"

A chuckle. "So, what do you propose we do then? Are you going to run for help? Or should we finish this?"

"... We aren't supposed to play with their reiatsu. That was our only rule."

"Rules are meant to be broken. Besides how could my piece ever hope to stand up next to yours? You went ahead and chose the anomaly. I simply countered you."

"By cheating!"

A grin. "Maybe so, but we're too far in to back out now. What will your next move be, I wonder."

I did promise more frequent chapters after all :)

Worst place to end? I know :) Tell me about it in a review!

-Mymomomo