The world twisted and cracked, crumpling into nothing in the back of her mind. Her shoes found the ground and skidded against it, feet almost silent, body almost invisible, black satin whispering along in shadows too deep to be real. There was nothing of her left, nothing controlling her legs as they ran, or her hands as they clutched the crocheted wrap around her pale shoulders -- only the tiniest sliver watching, through her own usurped eyes, the faint orange flicker of her own psychic glow reflect on the dark walls of the alley. And the humans couldn't even see that.

In desperation, she screeched in silence and clawed her way to the center of her own mind. Memories. Memories made her who she was. Experiences. What had happened a minute ago? Two? An hour? A day?

"Good morning, Ace," he said, one of those sly half-grins on his face. He had his hat on. His brolly was propped against the edge of the console. The time rotor wasn't moving.

"Hey, we've stopped. Where are we now, Professor?"

"Tut tut. Questions later. You've got to go get dressed."

"Dressed?" she parroted. Ace glanced down at herself. Black Docs. Black leggings. Black skirt. T-shirt. Bomber jacket. "I am dressed, Professor. What's the matter with it?"

"Dressed properly, I mean." The canny expression on his face widened into a full-out grin. For all of his secrets, this was one thing that was never hidden: the kind smile, full of warmth and care, catching all of the laughter in his face and none of the sorrow. It was comforting. Even if it did make him look like the cat that ate the canary sometimes, it usually meant he brought home more birds for her.

He stepped down from the console and threaded his arm through hers, pulling her back to the TARDIS corridor.

"Dressed for what?" she asked again, going easily with him. The Doctor wasn't the touchy-feely sort with most people, and she figured for him to pull her along instead of talking her into whatever it was, it ought to be something good.

"The theatre, of course. Wouldn't do for you to lounge about at home on your birthday, would it?"

The dress was hardly smudged. Amazing what sort of damage you could prevent when you were only half-corporeal. She wondered if he'd let any of his future companions wear it, if he found it after she disappeared. She liked to think he had something of a sentimental streak, but you never could tell with the Doctor. He could be patting you on the back one moment and sending your plans of world-conquest crashing down the next. He was like that.

Right through the back exit it went, not even unlocking the door first. Barely even opening it. The thing burrowing into her mind slipped into the club unnoticed, even in the dress that had to look oddly conservative here. Or maybe not. Plain black satin could pass for neogoth, maybe, or maybe the thing just bent light around her body and no one could really see. Ace tried to shudder as the clubgoers, wearing leather and chrome with rings threaded through every inch of skin, danced right up against her, heedless of boundaries. It didn't make it to her body. Never made it past her thoughts.

The music throbbed, making the air heavy, a percussive nightmare that rattled her teeth and deadened her hearing and turned every motion she wasn't making into an endless string of half-seconds, miliseconds. Zener's paradox. Always closer, not quite there. Her arms moved under someone else's control, waving over the crowd. Feet moved her closer to another. Hips swayed slowly, taking her right into him, a man in black jeans and black fishnet shirt and black dyed hair. She saw toxic orange reflect off a round stud in his eyebrow. He didn't.

Her arms came forward, sultry and soft around his neck. His pupils were huge, uneven, his breathing ragged and out of synch. His heart fluttered wildly, under hers; she thought bitterly of a double pulse and tried to scream out frustration. No sound. She pulled him forward, leaning inwards, bringing her lips close to his. The thing in her mind wanted her to kiss him. To transfer a part of itself to another, a parasite, an insidious, virulent presence that made him less a part of himself and thrall to an alien consciousness.

Ace shrieked into an echoing nothing. Coyly, as if it had been her intention all along, her body broke away, breathing across his cheek, whirling off into the crowd of dancers at a feverish pace. Ace didn't want to kiss him. She wanted to kiss someone else.

"Come on, how does it look?"

The Doctor rose from the bench in the TARDIS' wardrobe room and gave her a good look up and down, taking her hands after she'd spun for him, throwing out the long skirt. There had been a time when she never would have agreed to anything as ridiculously unsuited to blowing things up as this dress was, all smooth and shiny with darts everywhere to follow wherever the curves of her body went. There had been a time when she hadn't wanted anyone's attention. She thought now, just a bit, she wanted his.

"Lovely," he said, with feeling. He, of course, was in his usual, perhaps a bit more pressed for the occasion, with a solid waistcoat in place of the pullover of questionable taste. A gold watch fob was threaded through one buttonhole. The loosened tie hadn't budged an inch. "Chime of the ball."

"Bell, Professor. Belle of the ball." She'd seen him give impassioned speeches, off the cuff, that made hardened fascist dictators break down weeping. She suspected he pulled the cliché bit on purpose. She blushed, just faintly, anyway. "Thanks."

"Shall we?" He crooked his left arm, offering her his elbow. Ace took it, feeling a tug at her heart.

It was amazing how many people could fit in one room, even a room like this. Steel girders branched overhead, keeping a corrugated tin ceiling up. A hundred writhing bodies jerked in a hazy trance, half of it drugs, half of it the desperate need for escape. She didn't want to touch any of them, fearful deep down that if she did she'd catch whatever they had, whatever problems made them leave their homes, their friends, and come here, to dance, and wring themselves out, and flirt with death. It wanted to know them intimately, to kiss and drink their breath, to spread itself in tiny wisps of malignant smoke to every corner of the Earth. She raged against it, clawing at the slick glass wall it sealed her in, frightened, to become an unwilling spectator to her own swath of destruction.

The lights were hellish. They flashed and stuttered across the dull metal surfaces, disorienting. The orange glow was so unnervingly bright, as the thing in her mind saw all the lonely bodies, that it reflected from the roof, and off the stage. The singer screamed, sound bolting through the speakers, and she looked like she was on fire, blazing in the pits of damnation and despair.

"Here," said a voice, parched and cracking. Eyes wide, a raver tried to hand her a little paper cup. "Share the wealth."

Her hand took the cup and crushed it, and her other hand seized the boy's wrist and crushed that too. He was so high he barely felt it, only looked at his useless hand in puzzlement, trying to twitch one finger at a time. The nails she had so carefully lacquered for the occasion bit deep into the skin of his arm, drawing blood only a shade and a half darker than the glossy paint.

"Lovely manicure," said the lady, coming a bit closer to peer at the hand that held her glass of champagne. Ace had taken the glass off of a waiter's tray and for once, the Doctor had done nothing but smile. "Where in the world did you get it done?"

"I know a girl," Ace answered evasively. She did, too; the TARDIS had more gizmos and gadgets in its collection than she could shake a stick at. It was probably as much a pack rat as he was. She wondered who had picked it up from whom.

"It's so... unusual." She leaned closer, hovering over Ace's fingers, jet hair swaying forward to nearly brush her hand. Ace had seen faces like that, black and white movie faces, porcelain and charcoal and sensuous lips like she could never have. She thought of her own face, plain and square- jawed and unremarkable, and cringed. Was it any wonder he hadn't noticed? She wondered what Time Ladies looked like. Probably Helen of bloody Troy.

"Just a formula she's got. It only sort of dries like that," Ace explained lamely. She stared down at the thumb gripping her glass and followed the swirls of shining red and got lost in their scarlet tendrils. Maybe this was the last champagne she ought to have. When she looked up again, the other woman was holding her other hand, tracing the maze of crimson and scarlet on one nail with her fingertip. Her breath slid softly, casually across Ace's arm.

"I'd love to hear more about it," she said.

The night was cold and it was starting to get annoyed. Ace felt a tiny twinge of satisfaction that she'd kept the creature from spreading itself any farther, any faster this night. But she knew she couldn't keep it up forever, and the thing in her mind knew that too, and it was only waiting for her to tire and sleep. Then it would slither out and across the misty darkness, visting anyone it found with chill, and hunger, and death.

Ace hung on, grimly, praying that help was on the way. If not for her, then for the others.

It took her body stumbling into a park, slipping and sliding on the wet, rained-on grass, kicking off the patent leather pumps from the TARDIS' costume room and flinging them into the duck pond. She felt its appetite awaken again: there were humans, many, in the darkness. Touch them, and drink from them. Touch them, and use their lives for its own. Touch them, and own them.

"Isn't the show starting again?" Ace asked, backing into the balcony railing. Outside, the air was crisp and wet. It had just stopped raining. She fancied the woman's reflection in the puddles on the tile had an orange halo about them, flickering from her head like flames from a demon.

"Probably," she answered with a shoulder-baring shrug. Ace felt a chill roll up her spine, not from the marble rail but from the woman's advance, so close Ace could smell her perfume. "I'm sure we won't miss anything important."

Confused, Ace tried to look anywhere but at her eyes, dark gold brown with a tint of insanity. Pearls in her short, bobbed hair. Gold brooch on the neckline of her dress. Red, red lips that made the air heavy, and God what was going on? A cold night suddenly turned raging hot and she set her arms on the rails on either side of Ace, trapping her. Ace's head swam. Thoughts of going right over the edge of the balcony to escape fluttered through her mind and away.

"The Professor's going to be looking for me--" warned Ace.

"Your Professor," she purred, low and slow, dragging one dainty finger down Ace's painted cheek, "isn't here."

A breath of sweet steam burst from her bloody lips, the only breath she'd given all night, Ace suddenly realized, and then she lunged, touching and taking with a soft, deep kiss. Nothing was the right way up as control flowed from her and darkness flowed in. It brought a fleeting, wistful thought of *Doctor...* before it turned twisted and wrong, and she reeled, and went under in a wash of terrible, blackened pain.

Ace battered against the walls of her incorporeal prison until her thoughts bled. Her body stumbled, nearly falling. It caught hold of a tree with roughened, ancient bark, pulling itself to her feet. The scarlet lines scored across her palms closed in seconds. She raged and screamed against its agility, its speed and arrogance and sharpened sight that gave a thousand blazing auras meaning in the dead of inky night. She had visions, flash memories of what had nearly happened in the club, pulling someone close, matching their lips together like a puzzle from the dawn of time, and shuddered -- she wouldn't, not so long as she had the strength to fight. Wouldn't let this thing spread, using her body as a carrier, a toy in its deadly games. Wouldn't touch someone else. Not even him, she thought stoutly, not while this thing inside her brought mindless suffering.

She prayed, to a god that had long ago lost meaning for her, that he was gone, far away from here, so he didn't see her when she finally lost control. She had her chance -- she had five years of a chance -- and once it was gone, she only wanted everything to end. She'd go down fighting. It would hurt him to leave her behind, but at least he would only be losing a friend. She was the only one who needed to mourn what could have been.

Silently, it crept forward. Ace could feel her bare feet sinking into near- frozen pools of rainwater. Subtlety was gone from its motions now; it was starving, predator, desperate for new life forces now that the old had withered and died behind it, short-lived drones.

It froze. It tensed. It leaped. Ace screamed.

"Careful, now," the Doctor admonished, gentle hands pulling her back from the railing. He guided her across the tile, across the shimmering puddles and back towards the French doors, gazing at her with concern. "What's happened to you, Ace?"

"Nothing," she said, confused and scared. Had she really had that much to drink? "I'm okay. Really. Just a bit sick."

He didn't believe that at all. Ace didn't really either, but she hadn't any other word to describe that cold feeling, slithering up and around inside her belly, pain and revulsion just biding its time before emerging.

"Perhaps you ought to sit down," he said, keen blue eyes staring right at her, piercing like needles, like searchlights, like a soul diving into hers. She quickly snapped shut, folding like a doll into a chair in the lobby, suddenly terrified that he'd see, and he'd know, and things would get all trying and strange and then awkwardly fade away like nothing.

"I'll be all right," she said. "Just give me a moment. You go on and get our seats again."

"Are you sure?" The little feathery worry lines were starting to come out on his forehead again. He looked old. She imagined going back to Perivale on his arm and listening to the scandal it would cause. They probably thought he was twenty, twenty-five years her senior. It didn't bother her like she thought it would. There came a point where the age difference meant nothing at all, none of that silly generation gap stuff, no yawning chasm between them just because his hair was starting to go grayish and hers wasn't. Maybe after a hundred years it was safe to declare it didn't matter. Of course the Doctor was older than she was. The Doctor was older than everyone was, maybe older than he could even remember. That was just the way things worked.

She tried her best to smile at him. He smiled encouragingly back. His was the first face she could remember seeing real empathy on, untainted by her looks or her street voice or her school record three fingers thick. He'd been father figure, mentor, friend and cohort over the years, all without prejudice. Now there was only one more thing he could possibly be to her, only one more position he could hold in her life, and she wanted more than anything to suggest it, but always, it stuck in her throat. Stuck in her thoughts. Not here. Not now. Later, back home, in the TARDIS. Maybe.

"I'm positive. I'll be all right in a moment. Go on, go."

Lightning crackling across her skin, she tumbled to her knees in the wet grass, and inside her glass shell Ace let out a whoop of triumph. The humans it thought it saw were gone, vanished without a trace, and it was feeling some serious kind of pain from whatever field it had just been lured through. It snarled with her mouth, trying to stagger to its feet. Her head hit the top of the shallow bubble again and Ace felt liquid agony, filtered through the thing's perceptions.

"Let her go, anari." It brought her head up and for the third time in as many seconds, Ace gloated loudly at the back of its domineering mind. She knew that voice better than she knew her own, coaxed it into laughing during the day and heard it whisper to her in her sleep at night. Through the thing's extra senses, she saw white glare around him from head to toe, fringed with dolorous purple on the inside, nothing like the faint blues and reds and yellows of the teenagers inside the club. He wasn't human, not remotely, and it knew.

"Mine now," she heard herself say. "I deserve a body as much as you." She pitched one knee in the loam and struggled forward, limbs suddenly heavy and weak.

The Doctor glared at her, glared at it in her body, eyes hard as ice and ten times as cold. Sensation, pins and needles, crawled on her skin. The thing in her mind didn't like it.

"You're an indiscrinate killer," he said, never letting up for a second. It started bending, bowing, breaking, the walls it set up around her compressing, shifting outwards in new and unsteady ways. "You deserve nothing more than you get."

"No! I need her! You've had her long enough! I want to walk again...."

"You should have thought of that," he said dryly, "before you attacked my companion." She saw the hand that wasn't holding the brolly bring up a small, squarish box, and he deftly flipped a toggle with a quick snap of his thumb.

White light, searing fire that burned her eyes through closed lids, phosphorescent burning and gnawing and pain.... her own voice shrieked in torment, its destruction and her agony. Desperation brought it to her feet, half a step closer to the man responsible for its incapacitation, and then her skin twisted and her shell tore and orange malevolence burst through her and she fell forward, skidding down the hill to land at his feet, dress irrevokably ruined. She heard its cries of terror and anguish echoing in her mind from far away, and turned, squinting, to see it caught up in a web of bright lines, lashing the amorphous cloud together.

"Ace?"

He was on his knees, hands hovering close. She must have been a mess. Ace looked down at her own hands, at the rusty red adorning her fingers and the mud and kept watching as the first of many tears fell to wash it all away.

"It's me, Professsor," she managed, trying not to gulp in air in great wracking sobs. The hiss and crackle of the entity scrambling madly from one end of the forcefield to the other and back again registered, but faintly, on her hearing.

He came down farther, to her level, looking her squarely in the eye. He must be rooting around in there, she realized, rummaging through her brain to make sure every trace of the presence was gone. She never knew how far he went. She'd make sure it was far enough. All at once, she took everything she thought about him, every conflicting shred of love and annoyance and frustration and longing and comfort and jaunty here's-hoping- you'll-take-me-up-on-it, and felt it very fervently at him, whatever he was doing in there, with such concentration there wasn't room for anything to come in around it. Eventually, she ran out of things to throw at him, so she picked out the important parts and did it again. When she came back around and finally remembered to pay attention to what her eyes were registering, he was staring at her, startled still and pale, and there was a hand on the bare skin of her back, and it was trembling.

The thing -- anari, he'd called it -- thrashed back and forth at the top of the dome, stretching its net to the breaking point. Ace jumped as the knotted white spit sparks, and cringed when it started to unreel, splaying threads of nothing everywhere into the air. The Doctor must have been feeding his machine, she thought. That little knot of horrified recognition, distracting him at the wrong time, twisted up and lodged in her throat. Enraged, fire incarnate, the anari blasted through the cold, quiet air, blazing a blinding trail for Ace.

She twisted, rolled halfway around. The sodden dress bunched up around her knees and kept her rooted to the grass.

"Don't worry, Ace! It can't repossess what it's already lost!" The Doctor was shouting. The anari had nearly drowned him out with the crackle of malignant mindfire. She whirled around and snarled at the cloud, warning it off with anger and fierce obstinacy.

The anari struck, enveloping her in a clammy cloud, trying to thread its way into her thoughts again. Ace struck back at mist with a hoarse shout, clawing at glowing nothingness, until it spun in a dizzy vortex and whipped off in another direction. Towards him. Towards the Doctor.

White lightning struck again, spearing through the anari cloud. It keened, a primitive cry of frustration, and began to redouble its efforts, shrinking rapidly. It dove for the Doctor, and Ace dove for the Doctor, throwing herself at him, on her knees, in the soaked green grass, and as she blocked his lips with hers, Ace thought to herself that she was going to feel very stupid later if she were wrong about this being the only way the anari could take control of a body.

The very atmosphere screamed fit to burst eardrums as lightning struck again and again and again and the anari fragmented into random bursts and then faded in a despairing wail. Ace didn't let go until the last tendril of sound was gone, and the park was enveloped in perfect silence once again. And then a little longer. And then, without meeting his eyes, she broke away and settled down in the dark in the grass and pulled the skirt of the TARDIS' dress around her feet.

"I just wanted you to see that," she burbled, meaningless, at the ground. "I'm not even going to ask you for an answer because you're secretive and tricky and hate letting other people know what you're thinking and you'll never ever tell me anyway." Perfect water drops hit the grass, and she thought it was raining again until she realized they were only falling where she was staring. "But I want you to promise me something." Ace raised her head and put on her best stern face. "If they ever tell you I've gone over to their side, or I've left on another ship, or even that I've decided you can leave the planet without me, don't you believe them. Don't you *ever* believe them." She lifted a grubby hand and poked him, hard, in the chest for emphasis. Every syllable. Once more at the end to make sure he'd got it. "I won't ever leave you until I'm dead and gone, and so help me I'll find a way to haunt you after that. Promise you'll never believe them."

"Ace," he said, simply and a little sadly. She reached out and poked him again, in the same spot, before he could say more.

"Promise!" she demanded, scraping tears and not a little make-up from her face with her upturned wrist.

His eyes searched hers, his face a woebegone mask of a hundred things great and small. His hand was still on her back, after all that, with the same small tremor. Rummage about all you want up there, she thought defiantly, meeting his penetrating gaze straight-on. You'll only find more of the same.

"I promise," the Doctor intoned, quietly and solemnly, like a vow to some forgotten god. She took his other hand and cradled it in hers, tracking his weathered fingers with her own, reading every line, fine and deep, in his thousand-year-old palm, until she blinked, and blinked again, and her eyes tried to stay heavy and shut.

He squeezed his fingers closed around hers. She squeezed back, knowing only that he cared for her, and caring only about that.

"Let's get you home," he said, a low purr at the edge of her hearing. He tried to pull her to her feet, but she only came forward, sliding her arms around him under his weather-beaten coat, burying her face in his vest where it was warm and smelled of dust and old books, chamomile and catmint, hope and comfort, and stayed there for the rest of her life.