You can be two different people. Most of us are thousands of different people in the course of our lives, one for each context. There are actors who can change the shape of their face just with their expressions--just with a random bunching and stretching of muscles. So, when you say to me, 'I can't believe you didn't spot her for what she was', I would invite you to consider Marinette.

Without the mask and the costume, she's fragile as a china doll--with full cheeks and pink, glossy lips that look as though they've been varnished. In the time before, it was tough to see her walking down the street without wincing, because she was so perilously Marinette--always late for something, always a fraction of a second away from falling over, caring so much and feeling every setback, every snide remark, every thoughtless comment like a hammer blow.

I didn't know how she survived, but she did. She even excelled at it. She had to wade through the air that other people slid through, but she stood up to bullies, she encouraged her friends, she ran for election as student representative, and did her homework, and made beautiful things just for fun.

But you still knew it hurt her. You could still see her screwing up every fibre of her being in concentration whenever she raised her voice. Beautiful and disastrous. But, of course, I didn't know that then.

Now pull back from Marinette--maybe you've taken your eyes off her for a second, and you look back and she's not where she was, but you just assume that she's fallen into a bush or crawled under a park bench in sheer despair--and there is Ladybug.

For anyone who's ever seen her stride up to the mayor and demand his attention, or stand her ground in front of a nine-foot supervillain made of boulders, or sail through the air on the end of that yo-yo, or come up with a spectacular plan when she appears to be falling to her death from the top of the Eiffel Tower, the sweet, china-cheeked Marinette does not spring to mind.

Ladybug moves like a cross between a detective and a drill-sergeant--like everything is interesting and nobody is watching. Not a trace of clumsiness or self-consciousness. Not much grace either, but you get the feeling she had a look at grace early on and instantly dismissed it for wasting her time.

It's impossible to describe her--how she teases and poses and strides and struts and tells people what they are going to do in a voice so authoritative that you can see their muscles bending to comply before their brains have a chance to intervene. She is bossy and stubborn and won't take advice from anyone. She's a pillar of good sense and moral rectitude. She's my Ladybug.

Now guess--if you haven't already--which of these two lovely ladies I fell in love with. I'll give you a clue: it was not the one who was in love with me.

I'm two people as well, of course, but not in quite the same way. It isn't a confidence thing. Difficult to see how it could be, because I've had people looking at me--staring and sighing and even drooling over me--since I was inappropriately young for the experience.

But I'm happy on the rooftops. I'm happy wearing the mask and having no name and saying nothing of consequence. Most of all, I am happy being with her. The sound of carnage and destruction makes my heart hammer these days, because I know she isn't far away. I know I'll have a chance to be quick and survive on my wits and maybe--just maybe--be looked at by her.

Down on the ground, I am... well, nothing. Devastatingly handsome and rich, but trapped and sad and empty and inward-looking. We'll come back to that. But maybe mine is the more astonishing transformation. To go from pouting, air-headed model-boy to Cat Noir takes some doing, and I'm not sure it's the magic that's responsible. Only happiness--sheer, stupid, temporary happiness--can change you that much.

***

There was an after-party on the roof of the TV studio, after we'd helped Nino win the contest. Ladybug didn't want to stay, but she was besieged as soon as they yelled 'Cut', and it's fun to watch her kindness struggling with her impatience.

"Of course, of course--happy to help--always be here--please get out of my way."

I was besieged too, but it's such a step down from the adoring fans that besiege me during the day, I hardly noticed it. I followed her red costume like a beacon through the crowd, saying the odd word to people, but never really lifting my eyes from her. Alya wanted a picture and Nino wanted a hug, and I indulged them both for as long as I could before going after her. I could still feel a tingling in my shoulders, where her hands had rested on them.

She managed to carve a path through the crowd to the railings at the edge of the roof, but she stopped there, as if waiting for me to catch up.

Somebody had slipped a coat over her shoulders, in case she got cold. It's funny how she inspires these little protective acts, even though she never seems to need anyone or anything. She solemnly made arrangements to return it--because Ladybug--but she didn't defiantly shrug it off, which meant she was probably as tired as she looked.

I skipped up onto the railing and balanced there, with my stick hoisted casually across my shoulders. I'm never tired, not as Cat Noir.

"Walk you home, milady?"

She leaned against the railing. I could see her shoulders sagging, but she still had the energy to be snarky with me.

"Now why wouldn't that be a good idea?"

"Walk you somewhere?" I offered, unperturbed. "There's no five-minute warning, no Hawkmoth, no akumatized civilians-"

"Don't speak too soon," she said.

I shrugged. "I don't know about you, but I'm ready to go again."

She gave me one of her sweet, unwilling smiles. I really love those--not just a treat but a triumph. I make her happy, I think--although I've never worked out whether she considers that to be a good thing.

"You obviously can't walk me home," she said. "But we can walk."

I blinked. I hadn't been expecting her to acquiesce so soon. But I recovered magnificently, as I always do. I gave her a bow and offered my hand, but she was off already, slinging that yo-yo and scything through the air after it, flipping and tumbling at the crest of every swing, as if it was a matter of supreme indifference whether the line held or whether she smacked into the sidewalk down below. I followed as best I could, trying not to smile too much.

We stopped somewhere near the Champs Elysees. She sat down on the slates and leaned against a chimney stack, half-closing her eyes. I flipped over the chimney and landed, propped up on my elbows, at her feet. I had no idea what to do, but was too happy to care.

Everything was a game anyway, with us. There was not much chance of anything real happening, and sometimes I almost didn't want it to. I just wanted her to be her and me to be me and nothing to ever change between us, ever.

But at the same time, I really wanted her eyes to close all the way. I really wanted to ease that coat off her shoulders, and trail my lips along her neck, and hear her sigh. Just the thought of it made something tighten painfully inside me. I almost stopped smiling.

She tilted her head and rubbed her neck, as if she'd felt my imaginary kisses.

"I was really hoping for a quiet night in tonight."

"You mean to tell me you don't spend your evenings soaring over the city looking for evil-doers?" I said. "I'm disappointed."

I was delighted. The thought of Ladybug having a quiet night in--curled up in front of the TV in her mask and costume, maybe with a cat purring on her lap--was incredibly funny to me, and I couldn't help saying so. She narrowed her eyes irritably and said, "With loved ones."

That wiped the smile off my face--both because I don't have any, and because it was torture to imagine her with some. I hadn't even been happy about the cat on her lap.

But I was here, and the night was too beautiful for jealousy. Down below, I could see the lights of the passing traffic, like a jewelled necklace sliding along the road.

She suddenly looked at me and said, "This wasn't your idea, was it? For Nino to choose us as the celebrities he had to make dance for him?"

"I might have suggested it."

She closed her eyes, too tired now for snarkiness. "Kitty," she said, in a soft, despairing voice. "Why did it have to be dancing? Why couldn't it have been like...yo-yo skills or judo demonstrations or--or talks about crime prevention?"

I bit my lip to keep from laughing. She was too cute. She had the Ladybug portion of the world all mapped out, but anything outside of super-heroism was terrifying. There be dragons.

"Well, in the first round it was sufficient to just nod your head to the beat," I pointed out, "but I thought you'd probably be too kind to risk it."

She let out a long, slow breath that ruffled her fringe. "Damnit, I didn't even think of that!"

"Can't think of everything, milady."

She treated this remark with the contempt she felt it deserved. She was always trying to think of everything, all the time. Suddenly I could understand her exhaustion. I just couldn't share it.

I had every moment of that dance stored up in my memory--every self-conscious twirl, every time she cocked her head or rolled her eyes at me. The feel of her hands on my back. It was all there, teeming behind my eyeballs and making me grin uncontrollably.

"You didn't have to turn up," I said reasonably.

"Yes I did! He was so nice. You didn't have to turn up," she added. "I know you're not swayed by considerations of decency."

I spread my hands in a gesture of smug innocence. "I couldn't let my adoring public down."

"You really love being Cat Noir, don't you?"

"Who wouldn't?" I said, with the straightest face I could manage. "Why? Don't you like being Ladybug?"

She pulled her knees up to her chest and gave a squirming shrug. "I don't know. I like helping people. I know I'd be miserable if I couldn't do it. It's just...don't you feel like you're always having to bail out on your real life? I have a job and family and friends and--" she waved a hand vaguely--"studies."

"I know you're a high-school student, Ladybug. You don't have to be cagey about that."

"Well, anyway," she said, frowning in disapproval. She didn't like that I knew so much, and I didn't like that I knew so little. "I'm always late for something, or in trouble with someone, or letting somebody down, and I can't even tell them why--"

"You're lucky," I said, unable to stop myself. "No-one cares about me enough to notice that I'm gone."

She looked at me, startled, probably half-suspecting it was a joke. "Cat Noir..."

I panicked. This was not a road I wanted to go down, especially not with her. I winched my smile back in place and said, "Bugaboo, you're trying to do too much. You need to simplify. Concentrate on the things that are most important to you."

"They're all most important to me."

"OK, concentrate on the ones that make you happiest."

"They all make me happiest!"

I squinted at her. "You don't look very happy at the moment."

She tightened her lips, but didn't snap at me. I realized I was vaguely disappointed.

"OK, Little Miss Everything," I said, cupping my chin in my hands. "You keep on keeping on. We'll see how long it takes before you collapse."

I think she was reassured by my rudeness--either that or she'd just stopped listening to me--because she bit her lip and muttered, "Kitty... about what you said before. Is it true? Are you lonely?"

I straightened up. "Lonely? Are you kidding me? I have to fight my admirers off with a stick! Really, if you knew--"

She clenched her jaw. "Cat Noir, can you be real with me for five freaking seconds? We're friends, aren't we? Do you want to hang out more?"

I hesitated, surprise taking the place of panic. "Do you have time to hang out more?"

Again, she half-closed her eyes. I could almost see the weariness hanging above her, like an axe ready to fall. I had a wild, stupid urge to tackle her to the slates, just to knock her out of the way. But it didn't fall. She was fighting it, the way she fights everything--by thinking.

A smile struggled up to the surface of her face, and it stayed there. "You're my partner," she said, shrugging. "I'll always have time for you."

The smile was infectious, even though I felt frustrated, annoyed and tender all at once. I didn't want her to pity me. Although I really did. I sighed and said, "Ladybug, this is why you are always so miserable. And so perfect."

"Think about it, OK? I can manage an hour a week."

I blinked stupidly. "And this would be... what would this be?"

"Hanging out. Superhero talk. Absolutely no kissy faces."

"I will think about it," I said, because it was all I could say. I had a horrible nightmare-image of throwing myself to the slates at her feet and saying, 'Oh my god, thank you! I'm so alone!'

Instead, I said, "Ladybug, I wish I could get to know you on the ground."

"You'd be disappointed. I'm a lot less sure of myself down there."