A quick trip around Cardiff central, and Rose was able to find something that could pass as couture, or at least designer. She paired it with some sensible boots that looked great with the simple black dress, while still enabling her to run, should the need arrive.
When she'd stepped out of her room in the floor-length black velvet affair she'd picked up, her hair in ringlets around her face, the single strap leaving her shoulders bare, Jack had wolf-whistled loudly enough for her to feel justified in punching him in the arm, repeatedly, until he'd apologised.
She ignored the fact that his apology was interspersed with delighted laughter at the blush he'd brought to her cheeks.
There was a split to her knee that made getting to her leg holster and the gun it held easier, and after shrugging on a midnight blue suede coat, trimmed in thick black faux fur, Rose commandeered one of the Torchwood vehicles to make the three-hour drive from Cardiff to London.
Getting into the event turned out to be as easy as walking into a shop. She had an invitation, and her alias was on the list, and Rose swiftly began mingling with the other guests.
She felt a little out of her depth, almost everyone in the room knew far more about the geneticist's work than she had any true interest in, but she was able to grasp the basics.
On the plus side, the technology simply seemed to be more advanced than anything Jack had expected to see in the 21st century London, so the mission was more an attempt at making sure there hadn't been any alien intervention, than to interfere with the Professor's actual experiment, making her rudimentary grasp of the subject all that was required for the evening.
Despite her limited knowledge, Rose managed to make small chit-chat with a variety of people in the room. She knew just enough to ask the right questions and figure out that Professor Lazarus had been working on this project, whatever it was, for years. It had only been in the last few that he'd made any kind of serious progress, but that didn't raise alarm bells in her mind.
The fact that he'd been working on the project for so long actually soothed some of her concerns. Most hostile alien forces didn't have the patience to put in years and years of work to take over a planet, with only a few notable exceptions.
Still, she couldn't afford to exclude those rare exceptions, and until she knew exactly what the Professor's breakthrough was she wasn't willing to give him a pass.
She tried asking a few of the guests about the project, but no one who might have been willing to talk to her seemed to know any more than she did.
Eventually, the lights were lowered, and a spotlight shone onto the Professor and his device that had been placed in the centre of the room for everyone to peer at, and as Lazarus began his speech, Rose swiped a glass of champagne off a passing waiter.
"Ladies and gentlemen, I am Professor Richard Lazarus and tonight I am going to perform a miracle. It is, I believe, the most important advance since Rutherford split the atom. The biggest leap since Armstrong stood on the moon."
His guests were quiet, but many journalists were snapping pictures like their lives depended on it, and Rose had to force herself not to raise an eyebrow at the Professor's ego and to stay focussed on what he was saying as she moved closer, carefully weaving in between people to stand nearer the device.
"Tonight, you will watch and wonder. Tomorrow, you will wake to a world that will be changed forever," he declared before turning and climbing into his own invention and Rose frowned.
If something went wrong or didn't go as planned, and the Professor was the test subject, then who the hell was going to know enough about this contraption to help him? She wondered and she placed her untouched glass of champagne on the nearest flat surface.
Suddenly, the machine lit up, waves of energy radiating up the four external columns as they spun and began to exude enough bright blue light to make everyone reel back, raising hands to protect their eyes.
As the four columns spun, faster and faster around the central chamber containing the Professor, visible rings of energy began fluctuating across the machine, and Rose's jaw dropped in a mixture of awe and horror as alarms began blaring from the control panels set at the back of the room.
She manage to take two strides forward, a desperate attempt to do something to stop the machine, when she came to a stone cold stop as, over the alarms and the groaning sounds being produced by the Professors machine, she heard a familiar voice that made her heart still and begin racing all at the same time.
"It's gone wrong! It's overloading!"
Familiar brown hair, and the cursed black suit and converse, made Rose drag in a shuddering breath as the Doctor, her Doctor dashed across the room and started aiming the sonic screwdriver at the crackling and spluttering cables, while whole circuit boards sparked and began emitting plumes of smoke.
"Somebody stop him!" The shout distracted her from drinking in the sight of the Time Lord, and Rose's eyes snapped to the old woman who had shouted the order.
She didn't waste another moment, forcing herself to glance around the rest of the room and locate the event's security guards. They were in shock and slow to react as the woman continued wailing hysterical orders.
"Get him away from those controls!"
Rose didn't think through her actions, she didn't need to. She didn't stop to wonder what her sudden appearance might do to distract the Doctor. Instead, she moved forward in an instant and placed herself between the Time Lord and Lazarus Lab's security officers, a hand raised warningly and her fake ID held firmly in her hand as though she had some kind of authority.
"Stay back, he's helping!" She snarled.
She knew that the Doctor hadn't recognised her, or possibly even noticed her yet, when he shouted a response back at the elderly woman, the sound of the sonic continuing to buzz frantically.
"If this thing blows it won't just take this whole building with it, it'll take the whole street, is that what you want?" He shouted and Rose stared out the guard who was standing closest to the Doctor, her eyes dark and fierce.
"Stand. Down." She growled at the words, and they all did. The combined force of her perceived authority and the Doctor's dire warning nullified every threat in the room save the Professors machine and even that was slowly calming beneath the Doctor's mechanical jiggery-pokery.
As he pulled one last wire free from the console, the machine powered down and Rose stepped back to the edge of the crowd as a young woman ran towards the capsule and began tugging on the door.
"Get it open!" The Doctor shouted as the machine finished whirring. He'd not been able to see the young woman from the control panel, and ran to the front of the capsule himself, skidding to a halt when the door was yanked open before he could lay a hand on it to help.
The room collectively held its breath as Richard Lazarus pulled himself out of his machine, hands clinging to the edges of the door frame, only to reveal the miracle he'd spoken of when the man who stood there looked at least fifty years younger than the man who had stepped inside mere minutes before.
The journalist's cameras began snapping again, even more frantically now, and murmurs of disbelief and amazement began travelling around the room, but Rose's eyes were fixed firmly on the back of the Time Lord's head.
She studied everything about him, drinking him in. Everything from that amazing hair, to the black and white converse, and watched as the Doctor became quickly swept up in events, with a fascination and a powerful feeling of longing rising up inside of her that forced her to stay silent.
He still hadn't seen her, eyes fixed on the scientist with his back to Rose, while Richard Lazarus finally took two staggering steps out of his machine to address the stunned crowd.
"Ladies and gentlemen, I am Richard Lazarus. I am seventy-six years old, and I am reborn!" The man cried, and if Rose hadn't already felt that there was something distinctly wrong about this, then the Doctor's stiff, frozen form would have alerted her immediately.
She was suddenly, and surprisingly, glad that, for the moment, she hadn't been recognised. She needed to wait, and draw a few deep breaths as longing and fear bickered against each other in her stomach. She needed to wait, and watch, and see what to make of him. To see if he still...
Rose knew it hadn't been as long on this earth, between Canary Wharf and her reappearance, as it had been for her in the parallel world, but the Doctor could have spent centuries in the vortex before coming out of his Tardis shaped shell and reclaiming his life with a new companion. He could have been spinning around the universe for millennia before this moment in his timestream. He could have forgotten all about her and never mentioned her name, like Sarah Jane.
Or it could have been no time at all. Could it have only been a matter of days since he last saw her? Mere hours since they'd said goodbye at Bad Wolf Bay?
Part of her hoped so.
Hoped he hadn't truly had time to miss her before they were reunited, but a small, dark, hollow place in the back of her mind whispered that she hoped he had missed her.
Missed her for years, so that he'd know. So that he'd understand just how she felt standing there and watching him watch Lazarus emerge from his capsule, with the black-haired young woman standing beside him in a plum purple dress and sensible shoes who was, more than likely, his new companion.
She sucked in another deep breath, before releasing it in a sigh, and pulled her phone from her small shoulder bag, replacing her ID and forcing herself to turn away and move through the crowd while hitting her speed dial for Jack.
It didn't matter that her heart was screaming, trying to beat its way out of her chest to simply run into the Doctor's arms, Lazarus' invention was big. It was huge, and she needed more information.
"Jack Harkness' phone, this is Ianto spea—"
"I don't care what he's doing right now, Yan, I need to know who's been funding Lazarus Labs," Rose cut off her friend gently, keeping her voice low and quiet and the man cleared his throat.
"That bad?"
"Possibly. He's either a complete genius, or he's had help."
"What happened?" Jack's voice came over the phone and Rose hesitated. She could tell him that the Doctor was here, but now wasn't the time for Jack to face the Doctor. She needed him to focus, so she stayed silent.
"He just unlocked the scientific equivalent to the fountain of youth," she responded dryly. "We need to know who funded this project, Jack. Track the money, right?"
"Right. I'll text you the information when we have it."
She nodded, before remembering that he couldn't see her and sighed, "I'll keep an eye on things here. I've got a bad feeling about this."
There was a beat of silence and she could almost hear Jack's protective streak whirring to life before he beat it back down, trusting her to take care of herself, but he couldn't resist a parting warning.
"Take care, Rosie. Keep me updated."
She ended the call after reassuring him and glanced around the room, her eyes seeking out that unmistakable hair, and when she spotted him talking to the woman in the pretty purple dress, Rose wondered how she'd overlooked him before.
Forcing herself to focus past the thrumming of her heart still trying to escape her chest, Rose let her eyes continue moving around the room and eventually they landed on Lazarus.
He appeared to be coming back from changing into a fresh suit that fit his newly de-aged body, and Rose made a beeline for the man and offered her hand to shake.
"Professor Lazarus, that was astonishing. Simply astonishing," she gushed, "your invention is the work of pure genius!"
Rose made sure to keep her eyes wide with innocent amazement, and threw in her tongue-between-teeth grin that invited him to talk with her.
The Professor practically oozed his way into her personal space, and he raised her hand to his lips, leaving a lingering kiss there that had Rose forcing back a shudder and instantly regretting her decision to play the wide-eyed innocent.
"Why thank you, Miss—?"
"Lupin. Mal Lupin," she offered her alias, her smile widening. Despite how creepy Lazarus was, Rose was confident that she could get his guard down and if he thought her insipid then she might be able to get him to start showing off and describe the machine to her.
Genius' usually liked to babble she'd discovered, but the old woman who'd shouted for security when the machine was about to blow up approached and swiftly interrupted them, gripping her hands together in excited glee.
"Oh, Richard! People will sell their souls for this! To be reborn!" The woman all but squealed in girlish delight, and Rose stepped back at the flash of anger in Lazarus' gaze, forcing him to release her hand that he'd still been grasping.
He turned his gaze, suddenly much darker, on the woman, and the smooth smile he'd been offering Rose became tense and tight.
"Miss Lupin was just introducing herself Sylvia," the Professor began, drawing the elderly blue eyes to scan over Rose as Lazarus grabbed a passing platter of finger food and began eating, stuffing them into his mouth, chewing swiftly.
"And you are?" Sylvia asked Rose, superiority rolling off her tone, but Rose had barely managed to raise an eyebrow before the woman spotted the Professor and gasped out an exasperated and slightly shocked, "Richard!?"
"What? I'm famished!"
"Energy deficient. It's to be expected with this kind of process. You could do with a good, long nap really, or a nice cup of tea..." came the voice that haunted Rose's dreams, and her shoulders stiffened. The last thing she needed was the Doctor to reveal her real name, and Rose made a split-second decision that she hoped she wouldn't regret and that he would forgive her for.
She turned to face the Doctor, offering a grin as he froze in shock, mouth falling open to start babbling or maybe just to stare, but Rose took the opportunity to speak first.
"Doctor Smith? I haven't seen you in years! Not since that conference in Norway on the theory of dimensional travel, do you remember? We only had a few minutes to speak. The name's Mal Lupin," she offered as though reintroducing herself, and her voice was a mask of cheery recollection even as her eyes stayed locked on his, pleading and desperate for him to catch on.
A moment later, he did, his own eyes lighting up and almost glittering with excitement as a grin crept across his face. A hand went to the back of his head, running through his hair, and the familiar gesture turned her smile into less of a mask and more one of genuine pleasure.
"Oh! Yes! Yes, of course! I'm sorry I... I... I didn't expect to see you... here..."
"Energy deficient? You speak as if you see this process every day, Doctor Smith," Lazarus cut in, and when Rose stepped aside slightly so she could see both the Doctor and the Professor, Lazarus' expression was wary and curious all at once.
The Doctor simply stared at Lazarus blankly, his new companion staring at him in badly masked confusion, and Rose bit her lip to smother a smile when she realised that she'd thoroughly distracted him.
"Hmm?" The Doctor hummed questioningly before he shook his head and seemed to refocus quickly "Oh, weelll no. Not every day. But I have some experience with this kind of transformation—"
"That's not possible, Professor Lazarus has just invented this marvel of a machine" Rose interrupted, continuing to play oblivious, despite struggling not to just launch herself into the Doctor's arms.
"Using hypersonic sound waves to create a state of genetic resonance," the Doctor explained, showing off, his eyes sparkling as he glanced from Rose back to Lazarus, "That's... that's inspired," he complimented, nodding slowly and Lazarus' eyebrows raised in genuine surprise.
"You understand the theory then," he confirmed almost reluctantly.
"Enough to know that you couldn't possibly have accounted for all the variables," the Doctor added.
"No experiment is without risks."
"That thing nearly exploded. You might as well have stepped into a blender!"
Quite suddenly, Rose felt like she was watching a tennis match. The back and forth of the two men was at once mesmerising, and nerve-wracking, and oh god she'd missed this!
"You're not qualified to comment," the elderly woman, Sylvia, cut in with a sharp look of distaste plastered across her features, and Rose's eyes narrowed at the woman before she remembered she was playing innocent and oblivious and smoothed her expression out once more.
"If I hadn't stopped it, it would have exploded and taken half the street with it. People would have died," the Doctor said, how voice dropping an octave in unconscious warning not to push him,, but Lazarus either didn't notice or didn't consider the threat worth reacting to.
"Then I thank you, Doctor, but that is a simple engineering issue. What happened inside the capsule was exactly what I intended to happen. No more, no less. Simply look at me, I am living proof of my success."
"You've no way of knowing that," the woman with the Doctor suddenly announced, finally breaking her silence, "not until you've run proper tests!"
"I am all the proof you should need," Lazarus smirked, opening his arms wide for a moment as though to offer himself up for display and the Doctor's companion raised a disbelieving eyebrow.
Rose cut in then, her voice coaxing with an edge of concern and drawing the Professor back from his bragging a little.
"I'm sure Professor Lazarus and the labs will make sure everything is fine and certified before it's offered commercially, yes Professor?" She added, seeking the man's confirmation, while updating the Time Lord on the scientist's plans, but it was Sylvia who answered, once again interrupting Lazarus with a superior scoff.
"Of course it will be!"
"Commercially? You can't do that, it'll cause chaos!" The brunette burst out, startled at the revelation and Rose felt her lips tighten. Clearly a fairly new companion, she mused, before shoving the thought aside. Business first.
"A naive view. This won't cause chaos, but simply change. A chance for humanity to evolve, to improve..."
"Evolve or die?" Rose asked, head tipping curiously, and Lazarus turned a lascivious smile on her once more.
"Exactly, and in the most literal sense."
"This isn't about improving. This is about you and your customers living a little longer," the Doctor growled, his voice dark with anger, and Rose had to force back a smile. Rude and not ginger.
It didn't really matter that he was right, or that every fibre of Rose longed to respond in a similar vein, she repeated something her mother had told her as a child, in her head like a mantra, to stop herself recoiling from Lazarus instinctively.
'You catch more flies with honey than with vinegar.'
If she wanted more information, and she did, then playing nice was easier than the alternatives.
"Not a little longer, a lot longer," Lazarus corrected, almost gently.
"Indefinitely?" The Doctor asked, eyes narrowing, and Rose knew that look. The wisps of the storm approaching, but Lazarus was blind to the oncoming danger. Sylvia Thaw wasn't though, and interrupted their back and forth with a sharp cough.
"Richard we have some things to discuss... upstairs," she all but ordered and turned to walk away, clearly expecting him to follow her without question.
"Have a pleasant evening, Doctor Smith, Miss Jones. In a few years you will look back and laugh at just how wrong you were," Lazarus said, a tone of smugness to his voice that made the Jones' girl's frame stiffen.
It was when he turned back to her though, that was when Rose saw the Doctor tense.
"Miss Lupin, I hope we can continue our discussion uninterrupted a little later," he offered, and she let a flicker of surprise followed by a shy smile float over her features before nodding.
"Of course, Professor..."
He pressed a lingering kiss to her cheek, and Rose froze to stop herself from slapping him, letting him think her pause was surprise instead of disgust as he turned and followed after the Sylvia woman.
She glanced at the Doctor and his eyes were dark, almost black, and she swallowed hard.
"Miss Lupin—"
"Doctor—"
They both spoke at once, and then paused, and Rose's eyes dropped from his first, as he ran a hand through his hair, sighing in frustration.
"He's way out of his depth, isn't he?" The girl beside the Doctor asked, breaking the tension and Rose glanced up from the floor just in time to see the Doctor nod.
"He's got no idea of the damage he could have done."
"What do we do now?" The young woman asked softly, lowering her voice and shooting a nervous look in Rose's direction, but Rose slowly grinned at her, her smile only widening at the surprise she got in response.
"First we find one of their labs, and then use the creepy-as-hell DNA sample he just left all over me to find out exactly what's going on," Rose drawled calmly and the Doctor's slumped shoulders straightened out with a grin, his frame almost vibrating with suppressed excitement.
"Weren't you just fawning all over him?" The Doctor's companion asked, and Rose shuddered.
"Don't remind me," she muttered, "the things I'll do for information..." she shuddered again but anything else she'd planned to say was interrupted by the Doctor as he tilted his head towards a door on the far side of the room.
"Come on then, let's find a lab," he prompted quickly, a bright grin lighting up his features, "Allons-y!"
The Doctor led the way across the room, waiting until the sonic had gotten them out of the main event, before he spoke again, knowing that he wouldn't be able to contain the bubbling excitement in his chest.
"Martha Jones, meet Rose Tyler," he announced brightly, and despite the itch to snatch up her hand, forced himself not to turn and look at either of them as they moved through the corridors in search of a lab.
He heard Martha stumble, but ignored it. The sooner he could get to a lab and take a sample of Lazarus' DNA, the sooner he could pull Rose into a hug.
"I thought you said your name was Mal Lupin?" Martha demanded behind him, an almost accusatory tone to her voice, and the Doctor winced.
"Rose Tyler's a... difficult name to brandish about, so I use an alias. Mal Lupin. It's nice to meet you, Martha Jones," Rose answered, her voice soothing and the Doctor was relieved that she'd smoothed over the awkward introduction.
"But how did you get here?" He asked, glancing over his shoulder, and letting himself soak in her presence, even as the grin she'd been offering Martha vanished.
"With a lot of difficulty, but now is not the time, Doctor," she scolded, "let's find out what's going on here first, yeah?"
He was reluctant to drop it, and the repercussions of her presence here weren't exactly small, but he forced his thoughts to settle, and pushed thoughts of dimensional travel, parallel worlds, and the collapse of two universes to the back of his mind for the time being.
"Ah, a lab, finally," he muttered, buzzing the sonic against the lock again and holding the door open for the two women.
Martha moved to set up the equipment they'd need, and the Doctor gathered the supplies to collect the essence of Lazarus from Rose's skin. As they worked, the blonde stood patiently in the middle of the room, her velvet dress falling around her elegantly with golden tendrils falling across her shoulders and the Doctor found himself catching his breath at the sight of her more than once.
She was watching him as much as he was her, the Doctor was delighted to notice, but she only stayed still until he'd confirmed the sample collection and then she was cleaning her face and hands with a damp tissue.
Martha got to work immediately to start the machines analysing the sample, and all they could do was wait.
He didn't have to talk to a scientist or pretend he didn't know Rose. He didn't need to hold back for fear of damaging an important clue, and his mind had no riddles or mysteries to focus on solving until the results came back, and the Doctor felt his barely tethered control snap.
The way his arms curled around her waist and tugged her into his frame... The way she responded, fingers grasping firmly at the fabric of his jacket... The way he tucked his face into her neck, and she relaxed against him, letting her body form to his...
Apart from the ache in his chest, and the emotions gathering in his throat, threatening his composure, it was like she'd never left.
"I missed you!" She groaned into his ear, and the Doctor forced back the tears of relief in exchange for a bright laugh but he couldn't make himself release her.
He grinned against her shoulder, lips brushing against the soft skin her dress had left bare, before he tightened his arms a fraction more and picked her up, spinning in a full circle before dropping her back on her feet, careful to keep his hands against her until she had her footing once more.
"Of course you did," he deflected, "I'm fantastic, brilliant—"
"Egotistical," Rose deadpanned, but she was still grinning at him. He tried for a playful pout, but couldn't keep it up, his delight at her presence all-consuming, and he could feel a smile overtaking once again as he stared down at her, his fingers still brushing against her forearms, reluctant to release her entirely.
"Hello," he said softly, and she beamed up at him, her own elation shining back at him from her eyes, that were damp from her own barely controlled tears.
"Hello," she answered softly, and the Doctor giggled as her voice washed over him like a balm, but the beeping of the test results drew them apart and he forced himself to portion off the large section of his mind focussed on Rose Tyler and to concentrate.
"S'ready, Doctor," Martha called. Her voice was carefully neutral, but the Doctor ignored it and bounced over to study the screen she was sitting in front of.
He pulled his glasses from his inside pocket and slid them up his nose, just about managing not to react to the tiny hitch he heard in Rose's breathing. So she'd not been gone long enough for that reaction to change, he cheered mentally.
But despite far more of his attention being focussed on the blonde that was wise in the middle of a crisis, he forced himself to focus on Lazarus' DNA and sucked in a soft breath.
"Amazing..." he breathed out, half awed half terrified.
"What is it?" Rose asked, and she suddenly appeared in his peripheral, leaning around Martha to study the screen. Her hand settled on the back of Martha's chair, and like a magnet it drew his own to settle on top, his thumb gently stroking across the back of her knuckles as he answered her question.
"Lazarus' DNA,"
"I don't see anything different..." Martha said slowly, glancing up at him in question, but there was caution in her voice too. As though she was scared to get the wrong answer, and he felt his jaw clench on a sharp reminder that it wasn't a competition.
The last thing he needed was another Rose vs Companion situation.
"Look at it," he encouraged instead, nodding at the screen, and Martha turned back just in time to spot the structure shift and realign. Rose's sharp gasp told him she'd seen it too, and he grimaced.
"Oh my god, did that just change?" Martha spat out, and Rose leant back from where she'd been peering at the results. He let his eyes settle on her and seeing his own concern reflected back surprised him.
Since when had Rose been able to understand this level of science?
"But it can't have changed, can it?" Martha spluttered, but before he could answer Rose shook her head.
"It just did," she reminded the other woman, her voice soft and her gaze still on the screen, but her concern was settling into a soft frown of determination that brought a grin to the Doctor's face.
"That's three impossible things we've seen so far tonight," he told them, and while Lazarus reversing time's ravages of his body, and the shifting structure of his DNA were as fascinating as they were concerning, it was the third impossible thing standing in front of him that was the Doctor's favourite.
"And don't you just love it when that happens?" He asked, voice full of glee as he peered over the edge of his glasses at the blonde. Tossing 'love' out into the room, testing, waiting, and she didn't let him down.
Her eyes snapped from the screen to meet his, surprise flaring across them beautifully before she flushed and ducked her head, but he just beamed at her, quietly delighted at her reaction.
"That means Lazarus has changed his own molecular patterns," Martha interrupted, and the Doctor sobered. Now wasn't the time he reminded himself again and he sighed, turning back to Martha with a nod and sliding his glasses off his face and back into his pocket.
"Hypersonic sound waves to destabilise the cell structure, and then a metagenic program to manipulate the coding in the protein strands—" he began, but he paused when he caught Rose's grin from the corner of his eye.
"So, basically, he hacked his own body and told it to regenerate?" She asked tilting her head as she simplified his science babble, and the Doctor felt a thrill spark somewhere in his mind that she'd understood it enough to simplify it.
"Eeeh, rejuvenate, but close enough," he spluttered, but he couldn't summon forth the questions to ask about her new understanding because his brain fell silent under the sight of her tongue-touched grin.
"But they're still mutating now," Martha said, pointing at the screen as the DNA jumped and twisted again, and the Doctor swallowed down his desire to pull Rose back into his arms, and focussed.
"That's because he missed something. You really can't account for all the variables in a process like this," he grumbled, sighing as he leant back towards the screen, studying the readout again as he attempted to extrapolate the effects of the shifting DNA.
"Could end up with two heads?" Rose prompted, the quiet amusement in her tone pulling up memories of his less-than-stellar explanation of regeneration, but he nodded regardless.
"Something in his DNA has been activated and it won't let him stabilise..." he mused, distractedly, "Whatever that something is, it's still trying to change him," the Doctor continued, which is why he couldn't figure it out, he realised quickly. It wasn't finished yet.
Martha shook her head, seeming to be all but mesmerised by the constantly shifting DNA strands on screen.
"Changing him into what?" She asked, but the Doctor shrugged.
"No idea."
"I think we need to find out," Rose muttered, and when he glanced at her, she was frowning again. "That woman, Sylvia, she wanted to talk to him upstairs—"
"Let's go, then!"
Two strides across the room towards the door, and although he could hear Martha rise to her feet, he could already sense that Rose hadn't moved, and he froze, glancing back at her.
"I'll head back to the main room, in case he's down there already," she explained with a smile that did little to reassure him. The last thing he wanted, now that he'd found her, was to let her out of his sight, but she cut off his protest quickly.
"He wanted to talk to me anyway, so maybe I can get him away from the other guests, just in case," she explained, and the Doctor bit back his protests.
"Alright," he agreed reluctantly, "but be careful!"
"See yah on the other side," she shot back, grinning, "and no disappearing without me! I haven't even said hello to the Tardis yet."
Rose turned and left the lab without waiting for an answer, or glancing back at him, but she had no idea how much that demand had soothed his worries.
She was coming with him. She didn't want him to leave. She wanted to see the Tardis.
She wasn't going to get killed running after an insane geneticist without him.
"So... that's Rose?" Martha asked beside him, her voice quiet, almost timid, but he refused to address the silent questions, in part because he honestly didn't know the answers yet.
Instead, he just nodded, watching Rose move down the hallway with a determined stride, her dress swirling around her legs and her curled hair sliding around her shoulders making it difficult to tear his eyes away from her.
"Yup," he answered Martha brightly, spinning back to the medical student at his side once Rose stepped through the door at the end of the hall, and vanished out of sight.
"Well, come one then," he prompted quickly. "Let's go find out what's happening to the Professor."
He knew Martha had questions. He had questions of his own, but the priority was the mutant throwback wandering around a party with hundreds of guests ignorant to the potential danger, so he pushed everything else, including Rose, to the back of his mind and ran.