I lingered there, taking sips of hot chocolate, listening to Juleika's mother strumming her guitar. People really were amazing. Ten minutes ago, they'd been about to hurl themselves into the river--some of them had even managed it, and were still wet and shivering from the experience--but they were doing their best to be cheerful now, trying to keep each other's spirits up.

It looked as though some kind of spontaneous group therapy was going on under the city. People were gathered together in huddles, talking, nodding sympathetically, placing their hands on each other's shoulders.

"It's not like the other akuma-victims," Alya was saying, while I stared. "I mean, it's got to be traumatic anyway, getting turned into a zombie or a mummy by some new supervillain, but they never used the stuff inside your head before. Everyone here had their own reasons for jumping. The--" she made a face, "--the End just brought it to the surface, and made it impossible to resist. A lot of bad stuff's been stirred up."

"No kidding," I said. My hot chocolate had run out, and the cold was starting to creep back.

"It's ironic, really. You have no idea what a positive person she is, usually..."

"It's not her," I said, mainly to get her to stop talking. But it was true. Alya had no idea the extent to which it wasn't her.

I scanned the crowds again, trying to warm myself with the thought of other people's kindness, and saw something that made my heart jolt.

Master Fu was here. There was no mistaking that bright shirt, or the way he bent over his stick to make himself seem small and inoffensive, while watching your every move like a hawk.

At the moment, though, the stick was clamped under his elbow. He was nursing something in his hands, like a little baby bird, and I took two eager steps towards him before I remembered myself.

I wasn't allowed to approach him as Cat Noir. It was too risky. Hawkmoth was always looking for the Keeper, and anyone who spoke to Ladybug or Cat Noir out in the open would be suspect.

I turned back to Alya, and held out the Queen Bee comb. "Can I trust you to pass this on to Chloe Bourgeois?"

Alya didn't dignify this with a response. She closed her hand over the comb and said tartly, "Can you trust her to give it back?"

"Well, that's a problem for later," I said, smiling Cat Noir's sunny smile. Maybe there was some real sunshine behind it this time. It had to be Tikki he was holding. I didn't like that he was nursing her so gently--as if she was still frail--but it was some comfort that he had thought it safe enough to bring her along.

And she could tell me if Marinette was in any pain--although, if I wanted to fight the fog, it might be best not to know that.

I was shifting from foot to foot with impatience, but I still managed to say to Alya, "Could you tell Rena Rouge I need her? She's part of the plan. She's practically the whole of it."

I found an empty tunnel and transformed back into Adrien, while Plagg grumbled.

"I'm not a fashion accessory, you know. You can't just try me on and then take me off on a whim. Transforming is hard!"

"Really?" I said. "You've never mentioned that."

Plagg retreated into my shirt pocket, muttering something about getting some rest while he still could.

I turned back along the empty tunnel, but it wasn't empty anymore. Tendrils of fog were moving over the water like snakes, driving the cold in waves before them, honing in on me as if they could see.

My breath caught in the back of my throat. They were already too close to run away from. They were like groping fingers, and one of them curled next to my cheek, imparting a little sliver of cold.

But they had caught me without my costume. I wasn't Cat Noir. Could she see with the fog? She must have been able to see with the eyes of those zombified civilians up on the bridge, because she had moved them exactly where she needed them to be. Did she know who I was now, because the fog had found me?

"She's looking for you," Plagg said, through the thin layer of cotton. He sounded pretty unimpressed. Or maybe he was just unimpressed at having been disturbed again so soon.

"Can she track me anywhere with the fog?" I asked breathlessly.

"I guess so. Since you're the power-source behind the fog, I guess it would be pretty weird if she couldn't sense you. But don't worry. It doesn't have eyes. And if you move fast and think of something relatively cheerful, I bet we could lose it."

"No need," I said, half-smiling. I was actually having to work pretty hard to keep my positive emotions under wraps in that moment. This was an advantage I hadn't expected. "It's ideal. Think we can find our way through the catacombs to the warehouse district?"

I felt him stretching inside my pocket, and then his head grudgingly emerged.

"Cat Noir has a map of the city in his stick. But you can't just keep transforming like this without offering me cheese."

***

I tried to pick a route through the crowd where I wouldn't be waylaid by any school friends or kindly souls pushing hot chocolate on me. I didn't want to bring the despair back to these people, but I couldn't run the risk of losing it either. That meant picking my way carefully through the tunnels, from one deserted walkway to the next, biting down on my impatience to see Master Fu.

It took about twenty minutes to reach him. And by the time I did, he was watching my bright eyes and clenched fists as if they didn't bode well.

"Is she OK?" I said, in a tense whisper, when I was close enough not to be overheard.

"Tikki? Yes. Do you know you are radiating despair like a lighthouse?"

"Have to," I said, giving him a fleeting smile. "Can you hand her over please? And the earrings? I'd better not be seen talking to you for too long."

His hand twitched when he passed her to me, as if he was having second thoughts and then over-ruling them. But there were no doubts on Tikki's face. She looked at me with her wide, doe-like eyes and said, "Let's go, Adrien."

Her confidence warmed me so much that I could feel the fingers of the fog drawing back, as if I'd burned them. I had to summon up all the worst images of the past few hours--the line of blood snaking down Marinette's neck, the young couple clinging to each other as they leapt into the Seine--to draw them back.

"Who are you going to use as Ladybug?" said Master Fu.

He was watching me carefully, but he didn't seem as apprehensive as before. Maybe he'd been reassured by Tikki's confidence. Or maybe he had seen the love in my eyes when he'd handed her to me. She reminded me so much of Marinette--the real Marinette, not the one at the centre of the fog. And all my hopes of restoring that Marinette were tied up with Tikki. I couldn't help loving her.

"Nobody," I said. "If Hawkmoth sees someone else using Ladybug's Miraculous, he'll know it was Marinette."

"You are still trying to preserve her identity?"

"It's what she'd want me to do." I straightened up, trying to radiate the wide-eyed certainty that Adrien had always seemed to find so easy. "Trust me."

"Or rather, trust her?"

"Exactly."

***

There were not many pockets in the Cat Noir outfit, but I found one for Tikki to nestle in. Then I located Rena, persuaded her not to scream at the sight of the fog creeping up behind me, and led her through the tunnels, following the map in my stick.

For the first half-hour, she asked me questions, and I had to deflect them as cheerfully as I could, without letting the despair slip from my thoughts. But after that, she was silent. From time to time, I would see her glancing over her shoulder at the fog and shuddering. Cheerful as she usually was, it had to be getting to her by now.

We kept in contact with Carapace and Queen Bee through our ear-pieces. They followed Marinette at a distance and gave me a report of her movements. I cross-checked them against our position on the map until I was convinced she was following us.

"It's creepy," said Carapace. "The whole city's flocking around her like some kind of zombie army. If your plan was to draw her into the less populated areas, it's not going to work. She's bringing the population with her."

"Good," I said, glancing at Rena. "I want everyone to see this."

I went slowly, for her benefit. And I kept my thoughts dark and desperate for the benefit of the fog. It wasn't hard.

And then, after leading the fog around for so long that I could swear there was a layer of frost coating my back, the coms buzzed into life again. It was Chloe's channel, but it was not Chloe's voice.

"What are you doing down there?" said Marinette. The sound of her voice in my ear--as if she was leaning in close and whispering secrets--made the hair on my arms stand up.

Rena looked up in alarm, but I waved her into silence.

"Getting you your Miraculouses, princess," I said, in the most cheerful voice I could muster. "Um... where's Queen Bee?"

"I don't know. I threw her in the direction of the Trocadéro."

"With or without her Miraculous?" I asked, as if it was just a casual enquiry about the weather.

"With. She'll be fine. She's probably just taken a break to go shopping."

The sulkiness in her voice almost made me smile.

"You're going to give me what I want?" she went on.

"Always, princess."

"You're lying."

I took out my earpiece, and signalled for Rena to do the same. "Come and see for yourself," I said, and then dropped both earpieces in the water.

It was hard to do. The fog was heavy at my back. I felt as though I was dragging it along like an endless, water-logged cloak. And Marinette's voice in my ear--even if it had been the spirit of despair choosing the words--had made me think of better things.

But I didn't need better things. I needed the fog to keep following me.

"Was that a good idea?" said Rena. "Now we can't contact Carapace either."

"He'll have to improvise," I said, waving a casual claw. "Can he do that? You know him best."

This was a careful understatement, and she probably heard it as such. Since Carapace threw himself in front of any projectile hurled Rena's way, it seemed reasonable to assume either that they were lovers, or that Carapace really wanted them to be.

"Yes," said Rena, holding her head up defiantly, even though she was blushing. "He's got plenty of initiative. It's just--"

"--it works best under your direction?"

Rena glared at me, but I actually managed to smile.

"I know what that's like," I said.