It was like a nightmare from the first moment. I'd never seen her costume damaged before. There were smudged red tears on her arms, burn-holes in the mask, tattered edges, as if it was only fabric.

To be honest, I'd never thought about what it was if it wasn't only fabric, but suddenly it occurred to me to wonder whether it was Tikki--or maybe Tikki's spirit--stretched thin over Ladybug's flesh. Maybe Tikki would be as scratched and battered as the costume when she transformed.

I wasn't panicking yet. It was surreal--like the first, slowed-down moments after you drop a glass. Before the shattering, there's a second where you think, 'This can't be happening to me. I'm an adult. I don't drop things anymore'.

It was surreal to see Ladybug injured. I have seen this woman fighting on when one of her arms and one of her legs had been blurred out of existence. I have seen her running headlong into the jaws of a T-Rex and levering them open from the inside. She doesn't lie down on the job. She doesn't accept things. Her calmness unnerved me.

She was half-buried under the rubble--some kind of column had collapsed on top of her. I was too dumb to think at first, and tried to lift it. Then, when it wouldn't budge--when she said "Kitty" in her most soothing, reasonable voice--something snapped in me. I reached for the Cataclysm and disintegrated the pillar on top of her. I think I would have disintegrated anything that was preventing me from getting to her at that moment. It didn't occur to me that I was squandering the only weapon I had left.

Even after the pillar crumbled to dust, there was a kind of echo--a rumbling, like distant thunder. It was in the rubble underfoot and the impenetrable ceiling above us. The building was about to collapse.

Weirdly, it didn't unsettle me as much as the thought of what I might see under the pillar when the dust of the Cataclysm fell away. But she was--well, she was intact. Her leg was bent at an odd angle, and I could see more torn costume and bloodied skin, but everything seemed to be attached.

"Can you walk?"

It was a dumb question, but she wasn't even feeling well enough to roll her eyes at me. "Help me sit up," she said.

I didn't want to move her, so I dragged over a cinder-block and tried to prop her up against it. I was breathing fast--the dust kept getting caught in the back of my throat. I tried to straighten her leg, but she took a sharp breath and shook her head. I knelt down and examined it instead, turning my head to look at it from every angle, willing it to yield up some diagnosis other than the obvious.

"Are you a first-aider?" she asked.

"No, but I know a broken leg when I see one."

"I'm impressed," she said, with a small smile. It only made me angry.

"What happened? I thought you had the akuma!"

Her smile disappeared. "There were hostages. The ceiling was about to come down, I couldn't..." She trailed off, and then shook herself, as if she was trying to cling onto consciousness. "But it must have been some kind of trick--either that, or they were his people. Oh Kitty, I haven't messed up this bad since my first day on the job!"

"It's OK," I said breathlessly. To be honest, I was in no condition to take in what she was telling me. My eyes kept moving from her injured leg to the dark, unbroken ceiling above us. Not a single chink of light was showing through. I had good night-vision, but I couldn't see a way out of here. I could hear running water down below--we were probably above the catacombs of the old city--but without the Cataclysm, or at least a pick-axe, I didn't know how to get down there. Aftershock had my stick. And I was going to transform in four minutes.

"It's OK," I said again, scanning the walls for loose bricks or secret passages. "It's going to be OK, Ladybug."

She interrupted me--as brisk and impatient as ever. "I've got a plan."

I sagged with relief. "Oh, thank God."

"You're not going to like it."

I looked back at her, my eyes narrowed. I realized suddenly that her earrings were flashing. She must have used her Lucky Charm, not too long ago. But I couldn't see--and right now, couldn't imagine--a red and black spotted object that would miraculously get us out of this.

"Well?" I said.

She tried to lean towards me, and then grimaced. Oh great, I thought. Broken ribs too.

"Only one of us can get out of here, Kitty."

I knew just from that. I'm good at following her train of thought, filling in her half-spoken plans in my head. I knew what she was asking me to do. If I hadn't been struggling against the panic and the rawness in my throat, I would have yelled at her.

"You can't get me out," she went on. "I can't climb, I can't walk. There's a hatch leading down into the catacombs, but you'd have to drag me through miles of tunnels, and I doubt we'd get that far before the ceiling collapsed on top of us. But you can leave, and take my Miraculous. If you stay here with me, Hawkmoth gets them both."

"No," I said sulkily, "if I stay here with you, I can fight him."

She shook her head. "Nobody's coming in here, Kitty. The building's about to collapse--they won't risk it. They can just wait until this place comes crashing down and then comb through the rubble for our bodies. That's what I'd do."

"You would never," I snapped.

"Well, it's what I'd do if I wasn't so nice," she muttered. She was looking at the rubble-strewn floor now, as if she was afraid to meet my eyes. "There's something else. I think Tikki was injured at the same time I was. I need you to take her to Master Fu to be healed. She could die if she stays here with me--"

"You could die!" I protested.

"But Tikki's the only one who can capture Hawkmoth's akumas. Anyone can be Ladybug, but Ladybug's powers have to survive, or no-one will ever be able to fight him--"

I shook my head again. I would have done anything to get her to stop talking. This all sounded too cold, too rehearsed. She was talking like a martyr--not the warm, quick-witted Ladybug I knew and loved. It was like she was already dead.

And I couldn't tell her, could I, that I had lost my mother and was terrified of losing someone I loved again? Could she work out my identity just from that? Maybe not, but there was no time to get into a therapy session with her, even if I knew how to talk about it.

I was tempted to just pick her up and start running, but I didn't want to wrench her damaged leg. Plus, it's hard to resist her when she tells me what to do. I've kind of been trained to obey her--I guess all of Paris has. It's usually a very good idea. But I didn't trust her to do the right thing this time. Not the right thing for her, anyway.

I got up and started pacing, hoping that something would come to me if I moved--or at least hoping that I could find that trap-door to the catacombs, so that I knew where it was. Something told me she wasn't going to show it to me unless I agreed to her plan.

"There's something wrong," she muttered, tense and frowning, as she followed my motion with her eyes. "This is more than you not wanting to leave me--more even than you being afraid I'll die. What's the matter with you?"

"What's the matter with you?" I yelled, coming to a halt and rounding on her. "You never compromise like this--you never give up! What's happened to you to make you think there's no way out?"

She flinched back, but didn't look away from me. "All right," she said. "Maybe something has happened. But that doesn't change our situation. There was a time for refusing to compromise, and it was before I got trapped in here!"

"What did he do to you this time?" I said, almost too angry to speak.

It was the man she was in love with--it was always him, whenever her mind wasn't on the job, whenever she made a mistake, whenever she flirted with despair. It was always him. He had found ways of ruining my life that I couldn't have imagined, but he'd never gone this far before.

"It's not his fault," she said--and she sounded weary now.

Maybe she didn't have the energy to figure out why it wasn't his fault--or she knew she'd never convince me anyway--because she didn't say any more. Instead, she reached up and started fumbling with her earrings.

"No--" I said, shaking my head desperately. I think I even grabbed her hands and tried to prise them away from her ears. "Ladybug, don't!"

She gave me her cool, blue, honest, unflinching look. It didn't fool me for a moment. I knew she was scared. The problem was, fear had never stopped her from doing anything before.

"I've only got a minute left before I transform anyway," she said. "I've thought about it from every angle, Kitty. There's no other way. Plus, the Lucky Charm gave me this--" she fumbled in the wreckage beside her and brought out a red-and-black spotted crash-helmet. "I'm supposed to stay here. There's only one way to get Tikki out--and if Tikki doesn't get out, nobody is ever going to be able to fight Hawkmoth again."

I shut my eyes--half in panic, and half out of some bizarre sense of decency. It felt wrong to look at her transforming--like I was watching her getting undressed.

The insides of my eyelids blazed with the light of the transformation, and then it was dark again. I could feel her taking my hand, pressing something pointed into my palm--the earrings, I supposed. I just let them lie there. I couldn't decide whether I wanted to clench them tight or throw them at her.

"It's OK," she whispered. "You can look. I want you to."

I opened my eyes, but she was still Ladybug. She just wasn't wearing the mask or the costume.

I think that was what made me angriest, when I looked back on it later--the rightness of it, the obviousness of it. She had Ladybug's eyes, Ladybug's determined pout, Ladybug's hairstyle, Ladybug's figure, Ladybug's kindness and her sudden, adorable changes of mood. And she was Marinette.

There was no transformation. Marinette had been there all along, just as Ladybug had been there all along--every time I sat next to her in class, every time she stared and fidgeted and garbled her words around me.

Still, the rightness of it freaked me out more than any dramatic transformation. If she had turned out to be a werewolf--a zombie--a crazed half-insect lady--it couldn't have scared me more than it did to see the sweet, china-cheeked face of Marinette.

My breath caught in the back of my throat. I pressed a hand to my mouth. She must have seen my reaction and mistaken it for incredulity, because she smiled and said, "I know, right? Who would ever believe someone so clumsy and disastrous could be Ladybug? You know, this could work, Kitty. Say they find me in the wreckage of this building without my miraculous? What do they really know? That I've been found in the same place Ladybug disappeared? It doesn't prove anything. Maybe I'll seem like such an unlikely superhero that they'll let me go."

I shook my head again. I didn't know what it all meant. My thoughts were hopping about, trying not to look at anything directly, trying not to linger on any one fact for too long. She was Marinette. It was obvious, and yet it was unthinkable. I couldn't lose them both.

And all the things it might mean if I accepted she was Marinette - all the things I'd been ignoring - including that one big thing, still fresh in my memory: Marinette upset, shifting from foot to foot, blushing miserably and trying to get away from me. I'd hurt her somehow. Right before this all happened.

It was trying to make sense, but I wouldn't let it. I could feel the facts tugging at each other, like magnets trying to connect, but I held them apart, still desperately shaking my head. "This is worse," I said. "I can't just--"

She raised her eyebrows. "Oh, it's harder to leave me now you know I'm a civilian?"

"You're not just a civilian!" I shouted. "You're Marinette!"

A curtain of pebbles and dust fell down from the ceiling, loosened by my voice. She started coughing, but she was still angry. "I get it," she croaked. "Now you know I'm clumsy, disastrous Marinette--"

"No," I said, trying to yank my voice down by a few decibels. "Now I know you're sweet, kind Marinette--"

"But I always was," she insisted. "And I saved the world with you more times than I can remember. Listen to me, Kitty. Sweet, kind Marinette is not to be underestimated." She tried to smile. "Particularly not when they akumatize me."

"I can't leave you," I said, my voice ragged with the dust.

"Yes you can. They'll turn me, and you will fight me, and you will win." She was speaking very slowly, almost through gritted teeth, and I wondered whether she was in pain or whether this part was just really hard for her to say. "I don't tell you this often enough, Kitty, but you are very, very good at your job."

She held out her hand to me, and I saw Tikki, looking just as soot-blackened as Ladybug's costume had been before the transformation. Her antennae were bent and crumpled. Her eyes were closed.

"This is Tikki," said Marinette. "Please take care of her." Her voice softened a bit-and then, because she'd been keeping softness at bay for so long, she faltered. "I - she - she's been my only friend. At times."

"Ladybug," I said, reaching for her shoulder, but she sniffed and straightened and smiled.

"There's so much I want to tell you," she whispered. "So much I've always wanted to tell you - so many messages I'd like you to take, in case I--"

She stopped herself - I don't know if it was for her benefit or for mine - and sniffed again.

"No, you know what? Everyone I love already knows how I feel about them." Again, her mouth took on that tight, tense look, as if she was trying to clamp down on the words before she spoke them. "Except for Adrien," she said. "Tell Adrien Agreste that I love him."

I turned cold. Something prickled across my skin, as if Plagg was shuddering.

"What?"

She pulled me close and flicked the bell on my collar, smiling like the old Ladybug.

"Love you too, Kitty," she whispered.

She let me go - and I realized that her grip had been the only thing keeping me upright. While she'd been holding me spellbound - horrified - enthralled - she had managed to manoeuvre me over the hatch that led down to the basement. She let me go now, and I dropped like a stone. And even after I splashed into the tunnels beneath - even after I heard the hatch slam above me and I leapt up, hammering at it, fighting back the panic, shouting God-knows-what - I went on falling. There were only seconds between that moment and the building's collapse, but I swear, I was blundering around in those seconds for an eternity.

Marinette loved me. I could see all the consequences of that, rolling out in front of me. I followed them like a line of toppling dominoes, from one horror to another.

I'd been hurting her. For months. I had said I loved her like a sister. I'd asked her to come on my date with Kagami.

The two women I loved more than anything on earth were the same woman, and I could lose them both in the same second, just like I'd lost my mother. I was losing them both - it was already happening - and I couldn't get back up there.

The tunnels flooded with the collapse of the building. There were metal rungs embedded in the rock underneath the hatch, and I hooked my legs through them to keep myself from being swept away, as Tikki and the earrings were still clenched in my fists. I swam up and rammed my shoulder against the hatch, trying to force it upwards, the breath burning in my lungs. It almost gave way. I opened one of my hands to lever it up, and then lost half my breath in a stream of bubbles when I realized I'd let go of Tikki, and she was being swept away on the current.

I leapt after her, caught her, bundled her onto a ledge out of the water and waited, eyes stinging with frustration, until I saw her take a breath.

"I'll be back," I said, already turning to dive into the water.

I heard her stir and struggle to speak. "Cat Noir..."

"Two seconds, Tikki, two seconds - I'm not leaving her."

I dived under again, but it was pitch black now - I couldn't see the hatch or any of the pieces of half-broken timber swirling around in the water, trying to skewer me. I tried to plough through anyway, desperate to do something, convinced I could make out some kind of light in the murk ahead of me. But this time the current snatched me up and rammed my head against a cinder-block. I surfaced, spluttering, and heard Tikki's voice.

"Cat Noir, we have to go!"

"Two seconds," I said - or tried to say, but the water was caught in my throat, and it came out more as coughing.

"Cat Noir, she's right. We can't save her now, but maybe we can save her later."

I wanted to tell her that 'maybe' wasn't good enough, but I could see the consequences of that unrolling in front of me too. I'd get her killed. And then nobody would be able to fight Hawkmoth ever again.

All around us, chunks of the tunnel ceiling were tumbling down and splashing into the water. My teeth were chattering. I couldn't tell if it was the sudden dark or the bump on my head, but my vision kept cutting out, like a bad TV signal.

It was the worst thing I've ever had to do. It went against every instinct in my body. I had to grit my teeth against every horrible thought that occurred to me down there in the dark, as we waded through the collapsing tunnels. She might be dead already. Hawkmoth might be pawing all over her, going through her pockets, looking for her miraculous. He might not find her at all. She might be alone, conscious, dying by inches, with no-one beside her.

When we struggled up through a manhole cover and emerged, shivering, onto the Rue Petrarque, I looked back at the wreckage. I was still holding Tikki as gently as I could, but my other hand was clenched hard around the earrings. I could feel their points digging into my skin.

"She's alive," Tikki mumbled. Her voice was faint but full of conviction. "I can feel it."

I forced myself to breathe, but my chest was too tight to let much air in. I was still blundering through dark tunnels.

I turned my back on the wreckage, and staggered through the streets to Master Fu's house. At some point I transformed - I don't think I even had the wherewithal to duck into a doorway - and Plagg perched on my shoulder, peering anxiously down at Tikki. He was ragged with exhaustion too, but he didn't ask for cheese.

When we reached Master Fu's doorway, I hammered on it, torn between urgency and the terror that I would give him away somehow, and bring yet more trouble to my loved ones. Anyway, the urgency won out. I pounded on the door until I couldn't stand upright anymore. I could feel the ground sucking at me, slowing everything down, as if I was still wading through those flooded tunnels. I slid down with my back against the door until I was sitting on the front step.

"Tikki," I said, blinking frantically in an effort to clear my head. "Don't let me fall asleep."

I opened one shaky hand to look at her, but she was already unconscious. I supposed Plagg was asleep too, because he was uncharacteristically silent. I didn't want to look at him to find out. He had known all along. He'd let me break Marinette's heart. If I could have summoned up the energy, I would have shaken him. But I didn't have anything left. I was ready to die on that door-step. And when the door opened, and I fell backwards into the hall, I passed out before I even hit the floor.