A/N: Arrgh! I meant to get this done much sooner, ladies and gentlemen, but minor health debacles have left me a little preoccupied. As a result, I'm now playing catch-up with admittedly mixed success.

Without further ado, the latest chapter: read, review and above all, enjoy!

Disclaimer: Wicked is not mine. Also, this newest instalment will feature extremely disturbing subject matter and extremely visceral horror. You have been warned.

Somewhere in the darkness beneath the borderlands of Ix and Ev, the once-deserted caverns buzzed with activity.

What had once been a manor house and a few semi-detached sheds had expanded into a subterranean fortress complex, complete with guard towers, stone outbuildings, laboratories, barracks, greenhouses, and a six-foot-thick perimeter wall; by now it looked more like a small town than anything else. Even the main cavern had been expanded through geomantic spells, presumably to make room for more construction projects. And the population of this little settlement had skyrocketed: Boq clones swarmed across the property in tawdry green uniforms, hauling heavy loads, manning the guard towers, constructing new buildings, hunting for game, harvesting produce from the greenhouse, or brewing alchemical compounds in the labs.

In six months of experimentation and obsession, Nessarose had transformed her displaced home into a kingdom, and with the Grimmerie now in her hands, it was only going to get bigger from here. Under the light of an artificial sun, Nessa's sanctuary never ceased its interminable workload, remaining functional, efficient and relentless all through the night.

And at the centre of it all, in the operating theatre that the cellar had become, Elphaba worked and toiled and struggled to keep Glinda alive.

First, she did her best to anaesthetize Glinda before the operation began; then she cut away the blood-soaked clothes; then she began the healing process. Even with all her magical knowledge and the Grimmerie at hand, it was a desperate uphill battle to keep her condition from turning critical: the moment she'd removed the bullet, she had to staunch the bloodflow; as soon as Glinda was no longer in danger of bleeding to death, Elphaba had to attend to the internal injuries; and then, for safety's sake, she had to ensure that Glinda's wounds were properly cleaned and sterilized to prevent infection. Elphaba couldn't afford to use anything too ambitious in case it ended up doing more harm than good, so every step of the process had to be handled with the simplest and most practical healing spells.

The minutes dragged by, the spells blurring together into an indistinguishable haze of incantations, gestures, intentions and vivid green energies. Her arms ached, her head throbbed with thaumaturgical fatigue, her back screamed from hunching over the operating table, and exhaustion pressed down on her harder and harder with every passing hour. But she couldn't afford to stop; she couldn't even afford to slow down: she'd already lost Fiyero; if she let Glinda slip away as well, Elphaba would never forgive herself.

So on she went.

It took ten hours of non-stop work, but by the end of it, Glinda was somehow still alive; she'd have to rest and recover over the course of the next few days, and she'd need to be kept under observation for a little while yet, but for now, she was mostly out of the woods.

But it wasn't until Elphaba had cleaned Glinda up and magically lifted her into a proper bed that she finally allowed herself to relax enough to collapse into a chair, pour herself a glass of water from the carafe by the bed, and let exhaustion catch up with her. She knew she had other business to attend to, and a whole host of questions to put to Nessa, but Elphaba was simply too tired to budge from her seat; she would have gladly dozed off right then and there if she hadn't noticed the sentry watching from the door.

As expected, it was yet another Boq duplicate; he didn't respond to any of Elphaba's questions, nor do anything about him suggest that he was capable of speaking – or even thinking on anything other than the most rudimentary level. Whatever process she'd used to create these doubles, it obviously wasn't enough to replicate Boq's mind as well as his body. But even though she knew it was pointless asking questions of the silent guard, she still found herself almost overwhelmed with them: why did Nessa need so much security? Why had she made this house into a fortress? Did the advancement of the duplication process mean that the real Boq had already been given new legs?

Where was the real Boq? He couldn't have been hidden in yet another isolated room in the complex, could he?

More troublingly, why was the sentry watching Glinda of all people?

The more she thought about it, the more Elphaba found herself thinking back to the look Nessa had given her when she'd insisted on taking Glinda home with them: she hadn't argued at any point, nor had she even objected to the idea… but the expression on her face had been one of deepest irritation, as if annoyed at having to shoulder the burden of saving a life. Once they'd arrived back in the caverns and Elphaba had begun hauling Glinda to the operating theatre, the look on Nessa's face had been even more venomous than before.

What about the note slipped under her door? What about the fact that Nessa had deliberately set out to trick Morrible into taking them up to the roof – giving her forces the opportunity to invade from below?

And then there was the way she'd acted up there on the rootop; not only had she torn the Wizard to shreds without so much as a moment of horror or guilt, but she'd been almost impossibly blasé about Fiyero's death and Glinda's near-fatal wounding... although, the more Elphaba thought about it, a more appropriate word might be "uncaring."

But even with all the worrying implications staring her in the face, Elphaba had to believe that it couldn't possibly be as bad as it looked. Surely Nessa had just been reckless and desperate to rescue her that evening; surely she'd just been caught in the heat of the moment, too preoccupied with taking revenge on the Wizard to concentrate; surely she didn't actually hate Glinda.

She couldn't have wanted Fiyero and Glinda to end up dead, could she?

Elphaba tried to convince herself that she was just being paranoid, that she was going out of her mind with stress, heartbreak and fatigue. She couldn't actually believe something so terrible of her own sister; even after all the horrible mistakes she'd made, Nessa couldn't have done something like this – not with Elphaba's own life on the line as well.

She groaned and tried valiantly not to scream. How could things have gone so wrong?

Had there been something she could have done to fix this mess before it had started? Had she had the chance to save Fiyero and missed it? Was there a way she could have arrested Nessa's descent into madness – if only Elphaba had taken the opportunity? Had she made a terrible mistake by teaching Nessa magic? Or had the mistake been in not separating her from Boq by force all those months ago? Could she have ended the debacle in advance if she'd had Nessa join her as a fugitive – the Wicked Witch Sisters on a dual reign of terror across Oz? Or was there something else she could have done? And where was the real Boq in the midst of all these duplicates? And how the hell was it possible for him to have gone missing so suspiciously again?

Elphaba needed answers. She needed to sleep. She needed to think. She needed a glass of something stronger than water. She needed time to mourn Fiyero. She needed to know what was going on in Oz. She needed so many things that were out of reach or beyond possibility, and the more she thought about it, the more exhausted she became.

Try as she might, she couldn't get the guard to leave the room, nor could she abandon her paranoid ideas on what might happen if she left Glinda unattended here in the basement; so, rather than getting up and looking for a bed of her own, she simply drew her chair as close to Glinda as possible, hoping that it would be enough to dissuade any potential assassins.

Assassins, she thought deliriously. I'm actually imagining that my own sister might be trying to kill my best friend. Sweet Lurline, what happened to my life?

She was asleep long before she could think of an answer to that particular question.

Her return to consciousness was slow and disorienting, like struggling through the bog, constantly sinking back beneath the cloying waters and fighting for every second spent in the waking world. Dreams couldn't begin to cover the things she'd seen in her slumbering hours: again and again, she heard the gunshot echoing across the roof, saw Fiyero's body tumbling into the void, even felt the same explosive rage as she had that night. More than once, she could have sworn she awoke with tears in her eyes, only to slip back into the depths of sleep.

Fiyero is dead, she found herself thinking, as she drifted in and out of her slumber. Fiyero is dead, and I am to blame. Even if Nessa planned it that way, I'm still to blame: I made it possible; I made her madness a reality. In the end, it's still all my fault.

Eventually, though, Elphaba found herself clawing her way back into wakefulness; for a moment, she was aware of nothing other than the usual aches and pains that came from falling asleep in a chair, along with a mouth dryer than all the deserts bordering Oz. Half-conscious, she just managed to scoop up the glass next to her and gulp down most of the water without knocking it over or spilling it.

Then, as her eyes adjusted to the gloom, she realized with a thrill of horror that someone was standing over Glinda's bedside – had actually moved Elphaba's seat and bedside table away from the bed without disturbing her. And from that fact she could tell at once, long before the smiling faced and the full-body mantle dipped into view, that the intruder could only be Nessarose.

"What are you doing?" she almost shrieked.

"Relax," said Nessa. "I'm just checking her pulse."

"Well, you don't need to! I set up a minor enchantment to alert me to any change in her condition."

"I'm not going to hurt her, Elphaba. Contrary to what you seem to think, I'd never do anything to harm Glinda… as frustrating as she's been over these last few months."

"What's that supposed to mean?"

"I seem to recall her being the reason why you left me this time around. Still, I don't hold grudges: she's suffered enough, I think. Besides, it's not as if she'll be doing anything else to tear us apart now that she'll be staying with us for the immediate future."

Elphaba took a deep breath and got to her feet. "You say that as though she wanted to be captured," she said icily.

"She could have left with you, Elphaba – on both opportunities. She could have been staying with us from the moment she warned you of Morrible's crackdown; she could been down here with you and I from the very beginning. But she wanted to stay in Oz, even with the risks she'd just taken." She smiled sweetly, and added, "Sooner or later, dear sister, you have to stop giving people second chances."

In that moment, Elphaba's curiosity couldn't sit still a moment longer: she had to know, even if the knowledge would only bring her pain in the long run.

"Did you plan for everything that happened last night?" she asked softly. "Did you… did you want Fiyero and Glinda dead?"

She waited for any sign of hesitation, any sign that her sister was guilty over what had happened; months ago, she'd at least had the decency to look ashamed when Elphaba had confronted her over Boq's mutilation, even a little regretful. But when Nessa met her gaze this time, Elphaba couldn't see a hint of anything approaching shame or remorse in her expression: if anything, she looked almost unnaturally calm.

"It wouldn't have bothered me if they'd lived or died," she answered flatly. "I knew they'd be at risk from the note I left at your door, but it was the only way I could rescue you. Scrying had taught me much: I knew the roof was the best-protected part of the palace, so I had to make them think there would be an attack from the outside, and to do that, I had to make them suspect you. I knew they couldn't afford to kill their only hostage, so it was a fairly logical assumption that your friends would be the most likely to suffer. As I said, it wouldn't bother me if they'd lived or died. Fiyero was just… an acceptable loss. A sacrificial lamb, if you like."

For ten seconds, Elphaba could only stare in silence, caught between shock and anger. "...acceptable loss?" she exploded. "Nessa, do you even hear what you're saying? How is the death of Fiyero even remotely acceptable to you?"

"You're here, aren't you? You survived the night unharmed, you got revenge on Madame Morrible, and now you're back at home with me. And if all it cost was Fiyero's life, I'd call that more than acceptable in terms of loss. Frankly, Elphaba, if Glinda had ended up being flayed alive on that rooftop and put on display for everyone in the city to witness, it would still have been an acceptable loss."

"And it doesn't matter to you? Directly killing another living being and indirectly causing the death of a second doesn't even trouble you at all? The deaths you caused in those terrorist attacks don't register with you on any level? You don't even understand that-"

"That you were in love with Fiyero? Oh, I understand. But he wasn't serious relationship material, Elphaba: if it was, he'd have followed you to the Emerald City, made his feeling clear to you right from the start. Love's not real unless there's serious dedication. You and Fiyero just... weren't meant to be, not like Boq and I. But once we start branching out to world aboveground, there'll be others: you'll be over Fiyero within a year, and soon you'll find the man who was meant for you."

This time, Elphaba couldn't even summon up the vaguest trace of anger; she couldn't even speak. This wasn't just beyond belief, it was beyond comprehension: how was it possible for Nessa to even think like this, let alone say these things? Even the stress and guilt she'd been labouring under when she'd last seen couldn't explain this. Maybe Boq had escaped in the weeks following Elphaba's departure and the isolation had proved too much for Nessa's sanity – and perhaps that was the reason why she'd gone wild in creating clones to replace him, and why Elphaba hadn't seen any trace of the real Boq anywhere in the compound.

But no, that still wouldn't explain everything. Even if Nessa had spent the last six months alone, poisoned and driven mad by a thousand different experiments gone wrong, and it still wouldn't explain what had happened. There had to be something else here, something that would make sense.

"You needn't look so stunned," said Nessa, placid as ever. "Sooner or later, you're going to have to learn that you can't save everyone: you couldn't save the Animals, you couldn't save the people of Oz from the Wizard, and you couldn't save your friends. And you kept worrying about collateral damage: it only held you back when push came to shove."

"So now you think it was a mistake for me to try to avoid killing innocent people?"

"Would you like to compare results, Elphaba? I seem to recall getting a lot more done than you ever did in the last six months, and with significantly less expertise in magic and fewer resources on my side." Nessa smirked. "But again, it just proves my point: you can't save everyone, and trying will only ruin your chances. All you can do is care for your family... and your true love. That's why I built this compound – to defend those I love the most: you and Boq will be protected, cared for and loved for as long as it's within my power to keep you safe within these walls."

She absently adjusted her mantle. Not for the first time, Elphaba wondered why she was still wearing that: it wasn't as if she needed the insulation, for the house was kept at a fairly cosy temperature even down here in the basement. So why was she wearing such a heavy garment in her own house?

And then, just as she was starting to wonder if this bizarre clothing obsession was some symptom of her escalating madness, something under the mantle moved.

"What was that?" Elphaba asked.

Nessa contrived to look as innocent as humanly possible. "What was what?"

"Under your mantle. Why are you still wearing that thing, Nessa? What are you hiding?"

"Nothing sinister, believe me."

"Let me be the judge of that!"

There was another ripple of movement from under the cloth, and this time there could be no doubt: there was definitely something under the cloak – something alive.

Without saying a word, Nessa smirked, undid the buttons fastening the mantle in place, and parted it just enough to let the whole thing slide off her shoulders. And as it fell, Elphaba let out a strangled gasp of shock as she took in what her sister been trying to hide: under the mantle, Nessarose was completely naked except for the Ruby Slippers, her body pale, slender... and horribly disfigured.

Protruding from her right shoulder were four tiny fingers without nails, flexing helplessly as they tried to get a grip on something as yet unseen; around the other side of her body, a spindly vestigial arm was fused to her back, writhing and twitching spasmodically beneath her skin; her belly and chest were the worst, for here a head and neck had merged with her, the spinal column ending just above her navel. The head itself now sat pressed against her beasts, fused to her flesh by the left side of its translucent face, looking for all the world like a grotesque parody of a sleeping infant.

At once horrified and fascinated, Elphaba peered closer, but she could already tell that the figure now fused with Nessa's body was Boq.

"Isn't he beautiful?" Nessa asked, smiling proudly. "Doesn't he just complete me?"

Elphaba tasted bile in the back of her throat and sank back into her chair, frozen with shock. "What have you done?" she gasped. "What… how could you have done this to him?"

"It was an accident… but one I can't say I regret: it's brought us closer together than ever before, as you can see." She let out a sigh of contentment and ran a hand through Boq's hair, shivering in delight as the vestigial figure writhed unconsciously at her touch.

"It began as… well, my attempt to say goodbye to him, as strange as it seems. You see, in the days after you left, I wasn't in the healthiest state of mind: I was afraid, I was lonely, I was torn between staying here with Boq and going out to rescue you. For almost a week, I toyed with the idea of somehow saving you, but with all the new security measures you'd told me about, I knew I wouldn't get within five hundred miles of the palace before getting caught and killed. I admit, I despaired. I thought I'd never see you again, and I thought Boq would drift out of my life once his legs were restored – he'd go out one day in the hopes of seeing the sun, never come back. So I had this mad idea that I should just let him go and... set my affairs in order."

"You were thinking of-"

"Like I said, I wasn't in a healthy state of mind. And then I realized I'd overlooked something, a concept I'd been working on for a while before you left: there might still be a way for me to stay with Boq, so we could be together in mind if not in body; it was going to be one of the few ways I could little happiness to my life without him… and perhaps a chance for us to become soul mates of a more literal kind. Perhaps you know what I'm referring to?"

Elphaba gaped incredulously. "The experiments you were performing on Boq's brain," she murmured. "You weren't trying to read his mind at all; you were trying to merge them together! You were creating a symbiotic link between your mind and his!"

"Guilty as charged. My experiments were originally to allow us communication: Boq was still afraid of me, and I had days when I was too overwhelmed with guilt to even speak with him; I thought linking my mind to his would allow me to clear the air between us. By the time you left, I believe he'd forgiven me, but the need to remain with him was a priority. So, I did everything I could to forge a mental link between the two of us; I even used a technique copied from the Grimmerie. And there was where things went slightly wrong, and not merely in the physical sense. I didn't just merge with Boq, you see. I absorbed him, magically incorporated him into my body – and my mind. It wasn't a pleasant experience, I grant you: I was terrified when I saw his flesh oozing over mine like warm tallow, and once the nervous systems fused, the pain was almost beyond description; I had to take drugs just stop me from injuring myself in my agonies. I'm not even taking into account the sense of mental distortion I felt as our minds linked. Oh, Boq was screaming for every minute of it. But once the pain stopped… believe me, Elphaba, there was nothing but bliss."

The sense of nausea was stronger now, as was the chill in her limbs. It was taking all Elphaba's willpower not to vomit, and the more she looked, the more sickening it appeared. Frankly, it was hard to tell what was more horrific: Boq's current condition or Nessa's demented serenity.

She swallowed hard, took a deep breath, and did her best to remain calm.

"Nessa," Elphaba began unsteadily, "This is wrong. You have to disconnect: you have to undo whatever you did to Boq and let him go free before-"

"Impossible, I'm afraid," Nessa interrupted. "As I said, I've absorbed him: most of Boq's body has already been assimilated into my own. He wouldn't be able to survive without my flesh supporting his. Besides, how would I know how to correct this: the spells of the Grimmerie cannot be undone, remember? They can only be corrected. And frankly, why would you want to correct this?" She stroked Boq's cheek. "My beautiful Boq isn't going anywhere now!"

"But what if there's worse to come? What if there's some side-effect you haven't foreseen? What if you absorb even more of Boq?"

"I already am," Nessa giggled.

By now, she was already slipping the mantle back over her shoulders and clasping it in place, which at least hid the ghastly spectacle, though nothing could possibly hide the way Boq was twitching under the cloth.

"The absorption process is not yet complete. Since it began, I've been assimilating more and more of him; soon, he'll be completely incorporated into me. We will be two minds in one body. I'm already keeping his mind in my care as it adjusts to the transition." She tapped the side of her head by way of explanation. "He's stirring in here: even in his sleep, he recognizes you, Elphaba, and he's just as happy as I am."

"Nessa-"

That delighted shudder again. "I feel him whispering to me in sleep, snuggled up against my mind and dreaming of the sun. We'll go up there together one day, and I'll feel him rejoice inside my head. I'll feel him rejoice just as he did when I first built this sanctuary for the two of us. Oh, Elphaba, you have no idea just how much happiness he's brought to me in the last few months. Without him, I never would have found the will to fight the Wizard, never would have found the strength to save you."

And in that moment, Elphaba realized that Nessarose had finally parted ways with reality. Maybe it had been the absorption, the pain, the drugs, the psychic trauma, the stress of dealing with her new state of being, or maybe it was just the guilt of having done something so horrific without meaning to. Whatever the case, it must have driven her into the murkiest depths of insanity: denial, disconnection, loss of empathy, and a whole host of delusional perspectives on herself, her loved ones and the world around her… this could only be total insanity. No sane, rational human being could say the things she'd just said.

That would be easier for you, wouldn't it? A poisonous little voice in the back of Elphaba's skull whispered. An accident like that would acquit you of any blame for what happened to her. You don't have to think about how you left her alone with her thoughts, how you let her drive herself mad while you were off playing hero again. Oh, and let's not forget how, once again, it was completely pointless. Don't want to give too much consideration to that, do we?

No, the more Elphaba thought about it, the more she realized that whatever change Nessa had undergone – insanity or worse – it hadn't begun with absorbing Boq: it had started years ago, and it definitely hadn't happened all at once; it had been a process of attrition, one that had been getting progressively more brutal as time went on. Glinda's ill-advised matchmaking, Boq's unapologetic lies, and Elphaba's neglect had laid the foundations, and from there it had only kept building: the death of her father, her role as acting-governor, Boq running out on her, the isolation, the stress, and Elphaba's own bad reputation rubbing off on her had all done their part in driving Nessarose closer to a breakdown. And Elphaba's attempts to fix the problem had only made things worse in the long run, teaching her magic for her to use it to enforce her obsessions, keeping Boq by her side instead of letting him go, and never once repairing their dysfunctional relationship. And then the botched escape attempt, the move underground, and Nessa's descent into the unforgivable – and Elphaba had either failed to stop the worst of it from happening or simply hadn't been there to do so.

In the end, the merger had been the final straw: for years, Elphaba had been letting a fissure slowly work its way across Nessa's mind – and the events that had followed her departure from the house had transformed it into an abyss.

Over and over again, she'd failed Nessa. She'd neglected her when she should have been there; she'd indulged her when she should have said no, made excuses when she should have confronted her; she'd run away when she should have stood by her side; she'd even given her stamp of approval to an act of murder. And for what? First for the sake of a failed rebellion she'd believed more important that her own sister; then because she'd been guilty and anxious to make up for her earlier failure; then because she'd been gullible enough to fall for Morrible's gambit; and finally... because she'd stopped caring entirely. And in the end, Elphaba had failed Glinda, Boq and Fiyero as well, and left Oz even worse off than ever before.

She couldn't do this any longer. She'd been sleepwalking through the last year of her life, watching her initiative slowly dry up and her confidence turn to dust before her eyes as she'd gradually abandoned all hope of changing Oz for the better. Well, she couldn't afford to waste another minute on this self-pitying, self-destructive malaise: she was going to set things right here and now. She was going to find out where Nessa was keeping the Grimmerie, and then she was going to use all the knowledge and power at her disposal to restore Boq to his old self – no matter what Nessa said about it – and then she was going to get him the hell out of this lightless pit, ideally with Glinda. By now, she didn't even care that Boq's infatuation with Glinda was unrequited and unhealthy; frankly, anything would be better than letting him stay with Nessa.

Once that was over and done with, she was going to stay with Nessa for as long as it took to cure this insanity. And if that was ever complete, if she could somehow get her sister to understand the horror she'd just inflicted, then the two of them were going back to Oz to clean up the mess they'd made of the country.

Sighing, she got to her feet: quite apart from the need to clear the pin and needles in her legs, it was high time that she broke the bad news to Nessa. She couldn't afford to be delicate around her feelings this time around. So, preparing herself to be brutal and uncompromising with Nessarose for the first time in months, she took a step forward-

-and promptly concertinaed backwards into her chair.

Nessa tutted disappointedly. "I'm going to have to up the dosage next time," she mused. "That should have taken effect much sooner."

It took Elphaba a grand total of three seconds to realize what had just happened and notice the strange-looking residue at the bottom of her glass. She tried to rise again, but her legs didn't even respond this time around; the pins and needles had escalated to total numbness.

"What did you give me?" she whispered.

"Just a sedative – a local fungus I've had my men harvest. Mildly paralytic, but you'll be fine."

"But-"

"It's alright, Elphaba. I knew you wouldn't approve of anything I'd done, and I knew you'd do your best to undo all my work. So, I've taken the burden of doing the 'right thing' out of your hands: you won't have to lift anymore, sweet sister. You and Boq will stay here with me in safety and comfort for as long as you live." A ghastly smile brightened Nessa's pallid features. "Maybe even longer if I have my way. After all, I've had more than enough taken away from me; I think it's time I started taking back instead."

"But what about-" Elphaba's eyelids fluttered wildly. "What about Glinda?"

"Oh she'll be here with us as well. Don't worry: as long as she's on her best behaviour, she'll be taken care of."

By now, Elphaba couldn't even speak.

Nessa smiled pityingly down at her. "I said I'd be strong for you, Elphaba, and I meant it: you can let yourself be weak now. As a matter of fact, I think I'll have to guarantee it…"

A/N: Care to guess what happens next?