Rose wandered over to a set of shelves in the library, running her hands over the glossy spines of the books and simply letting herself revel in the effect of being on the TARDIS again. Her fingers traced absently over book after book, finally coming to rest on a slim collection of Dickens' short stories, which drew a soft smile. The Doctor had read this to her, first when he'd been leather and gruffness, putting on a show after not-Naples, and then again when he'd been new and pinstriped, trying desperately to show her that he was the same man, that he was still her Doctor, despite the plethora of hair and the unending gob.

She plucked the book from the shelf and moved back to the couch where the Doctor (and he always was her Doctor, no matter the wardrobe or the hair) was, unable to stay far from him for too long. Settling on the floor with her back to the couch, she wrapped an arm around his leg, resting her cheek against the soft wool of his suit-clad knee. As she began reading, her thumb absently caressed his ankle and his manly, hairy shin, his cool skin warming under her touch.

The Doctor hummed out a sigh a relief when Rose moved back over and touched him again and his left hand automatically went to the top of her head. He hadn't gotten far in the book with her on the opposite side of the room, his eyes continually darting up to follow her movements, his body calling out to him to bring her back, to keep her near, to keep her with him. The logical part of his brain attributed this frantic dependency to her long absence and his fear that this would all turn out to be a cruel dream, but he also knew that this unquenchable desperation for her company ran deeper than just that (although that slight caress she was giving his ankle was quite distracting). He wouldn't previously have ever thought his ankle to be an erogenous zone but Rose was, as ever, continually proving him wrong.

Since Rose's reappearance after her interactions with his past, her presence now felt like a visceral, fundamental requisite to his existence. He'd always wanted her beside him, almost since the moment he met her, and he had loved her practically that long as well (even if he had been loathe to admit it), but those feelings were so much more now. The unfinished bond between them was singing with the need, pining for completion, overwhelming in its demand to filled. Sighing, he forcibly drew his attention away from Rose's warmth back to the book. He needed to decipher what exactly was happening to them before it inevitably went further. Reading the little his book had to offer, the Doctor discovered everything he could about the mating bonds he had vaguely remembered from his dusty old Academy days.

Rose, for her part, was trying to focus on trains and ghosts but the feel of the Doctor so close beside her was intoxicating, almost irresistible. Had she always been this fixated on him? Her attraction to him and her love for him had grown every day she'd spent with him since 'Run!', but this was an altogether new type of sensation. Of course, there was only so much time one could pretend to read gossip rags while actually staring at Time Lord's bums so she'd had a number of fantasies, human hormones and all. But now, all she could think about was having his skin next to hers, legs tangled in sheets and hands fisted in hair. She had always wanted him (in any body, it seemed) but this fixation was getting ridiculous. Ol' Charley boy was doing nothing to hold her attention at the moment. Finally, she set her book down and pressed her free hand against the floor, tentatively reaching out to feel the TARDIS, asking the ship for a distraction so she didn't just jump her Time Lord's bones right then.

The brilliant gold of the TARDIS seemed amused with her a moment, reveling in Rose's happiness and then the golden presence flew to her mind, rushing in as though she had just been waiting for Rose to initiate contact like this. The dizzying flood of the immense new presence was overwhelming at first, making Rose flinch and close her eyes. At her reaction, the surge immediately slowed and glowed an apologetic yellow mixed with warm pink love and orange excitement. It made Rose realize that the TARDIS had missed her too, that she was needed not only by the pilot, but also by the Timeship herself. Rose marveled at the feeling of interacting with the TARDIS like this, shyly sending back a wave of gratitude and love to the ship.

She had always felt close to the TARDIS but now, like her bond with the Doctor, everything felt much richer, much more vivid, since she had returned from the parallel universe. She could feel the TARDIS' beaming joy at her attempt at deeper communication and the ship was practically vibrating with excitement. Rose was about to try the communication again when suddenly the cobalt blue of the Doctor's mind shot through her, frantic and confused, desperately enveloping her and mentally yanking her back from the TARDIS' affronted glow.

Dazed a moment from sudden disconnect, Rose's eyes shot open to find a wide-eyed, terrified Doctor kneeling in front of her, his hands on her head, thumbs pressed to her temples, book discarded carelessly on the floor. He was shaking and his chest was frantically heaving despite his respiratory bypass and his expression was wild. "What is it? What's wrong?" she asked, confused and frightened by his fear. There was nothing in the TARDIS that could harm them, surely?

"What do you mean 'what's wrong'?" the Doctor snapped as his eyes darted across her face and the dark, desperate navy stripes in his mind pulsed with anxiety, his voice high and tight. "That was - you were - I thought -What the hell was that?"

"What was what?" Rose asked, confused. All she'd been doing was sitting here, speaking with the TARDIS.

"You, and, and...you!" the Doctor sputtered, his hands falling from her temples to his sides as he sat back on his heels, watching her warily, his frenzied distress still pounding on the edges of her consciousness. "I was just getting ready to tell you something about the bond but then I looked down and you were all glow-y and doing something odd with your mind and -."

"Hang on...'glowy'?" Rose asked, frowning at him.

"Yes, glow-y! Golden glow-y. Bad Wolf glow-y, Rose!" he growled and she could feel his agitation and the lingering residual fear from the Game Station shot through her from him. He was re-living her 'death' then and was even more terrified of it now. "I thought I was losing you," he finished, quietly, his voice little more than a whimper.

"It's ok," she soothed. "I'm not going anywhere. I'm here now and I'm staying. Stuck with me, remember?"

That comment earned her a small, wan smile without much feeling behind it, but it was a smile nonetheless. His eyes still burned with worry and concern. "What were you doing?"

"The TARDIS and I were just having a chat," she responded, reaching out to lay a comforting hand on his shoulder, trying to stop his agitated fidgeting. "A bit of girl talk, I guess."

"What?" he asked, gaping at her. The old girl had always been oddly fond of Rose and he'd occasionally felt her communicating in a light, rather vague telepathic connection with the TARDIS, particularly after the Game Station incident, but nothing like that had ever happened before. He would have remembered. And fixed it.

At that last comment, the TARDIS mentally poked him, irritably. Apparently she didn't think anything needed fixed.

"You heard me. I was talking to the TARDIS. Remember? You noticed it when we moved her to my flat in Pete's World." His gaze darkened further. He had noticed it back then and, at the time, it had been an fascinating anomaly. Now, however, it seemed like a dangerous risk. Unheeded, Rose continued, "The connection has been a lot more intense since I met you back then and even more since I got back to you, this you, but I don't think it's anything to be worried about -"

"Medbay. Now," he said shortly, pulling Rose up with him and scooping the Gallifreyan book into his hands

"Doctor, I'm fine," Rose tried, struggling to keep up with him as he set off through the hall at a very fast pace. "Anyway, if something was wrong, the TARDIS would have -"

He came to an abrupt stop in the middle of the corridor, causing Rose to crash into his back. "Rose, please," the Doctor said, his free hand coming up to cup the side of her face like the man he used to be. "Just let me...I just...I need to know. I can't be without you. Not again. Let me do this."

"Ok," Rose answered, reaching out with her mind, trying to console him. They both shivered at the contact, slight though it was. "Whatever you need, Doctor."

He looked at her closely, his mind grasping at the edges of hers, held back by the thinnest of threads, greedy for the contact he had been denied for so, so long. The desperately hidden whisper of madness in his soul howled threateningly at the memory of her loss, that narrow crack in his sanity which had always softly taunted Rose from the depths of his eyes, whether blue or brown, widened in his vulnerability.

Rose wondered briefly what he would have become if she hadn't returned and if Donna and Martha hadn't been there for him. Would his cracked and damaged psyche have broken? Would that whisper of madness become a roar, drowning out the good man she knew for the madman he could become? Terrifyingly, the TARDIS flashed her dark red and orange images of fire and death and she knew the answer. She shivered at the knowledge that she held even a modicum of control over such a powerful man. As she stared back into him, unflinching at even this image of him at his darkest, his gaze shifted, the shadows quickly fading into bold desire. The Doctor pulled her into a fierce kiss, his lips claiming hers, as though trying to prove to himself that she was here and that she wouldn't leave him.

A moment later, he had her pressed against one of the coral walls, his arms wrapped so tightly around her that he was practically touching his own ribs, as if holding her this close to him would keep her from ever being hurt again, as if he could make her a part of himself and they would never have to be alone again. The Gallifreyan book in his hand dug into her and his lips on hers were harsh, almost punishing, but she didn't seem to mind. His hips shoved forward into hers and he growled as she whimpered, both of them lost in the sensation.

"Doctor, we can't. Not here. Not like this," Rose managed to gasp out, as his mouth moved from hers to her neck, biting and sucking at the skin exposed there from the open collar of his oxford. "You said -"

"Mine," he interrupted, in Gallifreyan, and ground his hips against her harder, perfect friction as she moaned.

"Yours," she answered in English and he rewarded her with another deep kiss. His mind was pouring over hers now, reaching out with eager, avid tendrils, twining her ardent mind around his. Soon, there would be no going back. Not that he ever wanted to go back. Or that she did.

Suddenly the TARDIS intruded, prodding both of them and breaking the intoxicating connection. The abrupt abeyance made them feel as though they were teenagers having just been interrupted by an angry mum. The Doctor sprang away from Rose, looking deliciously disheveled and guilty, lips swollen and panting. She imagined she made a very similar lusty picture and flushed, both with embarrassment and arousal. The TARDIS seemed to smirk at them and then flashed the corridor lights, making the Medbay door glow brighter.

"Apparently we're wanted elsewhere," the Doctor said with a wry grin, letting Rose watch as he adjusted his trousers slightly and then reached out to take her hand with a wink. "But we're coming back to corridor sex sometime soon. It's on the list."

"Sounds good to me," she laughed, gladly taking his hand and following him into the Medbay. She hopped up onto one of the tables and contemplated the last time she had been in here. For her, it was only a few days ago, after his regeneration into his ninth body. For him…

While they had been out shopping for a gift for Jackie, not long after Olympic flames and not-blue buckets and just before red rocks and idealistic promises, Rose had scraped her hand on a stone block. The Doctor, who, despite his babbling assurances otherwise, had been extremely protective and clingy after that night under the London stars, had immediately rushed her back to the Medbay for treatment, barely leaving Rose enough time to toss a few coins to the vendor for Jackie's bazoolium.

He had stood between her knees and lovingly, tenderly, healed the small scratch on her hand, muttering fondly about her ridiculous talent for getting into trouble no matter where they went. Rose had been able to feel the undercurrent of his worry then and their relationship had teetered so closely to the edge of giving in that night. He had almost kissed her, she knew he had, but at the last moment he had shaken his head sadly and jumped away, burying the moment under a shower of meaningless words.

"I wanted to kiss you so badly," the Doctor murmured, fiddling with an instrument in his hands, apparently re-living that moment as well. "I nearly did. I nearly told you everything but it just...it seemed so hard. If I'd only known back then..." He took a deep breath through his nose and then pointed the wand-like thing in his hands toward her. "You, lay back and hold still."

"It's 'lay back and think of England', Doctor," she teased, but did as he instructed.

"Oh, when we get to that, I can assure you won't even be able to spell England," the Doctor responded, cheekily and Rose squeaked in surprise as one of his cold hands unexpectedly snuck its way under her shirt to give her hip a quick squeeze.

"Promises, promises," Rose continued, closing her eyes against the bright blue light that was suddenly shining above her from yet another instrument of his. "What're you looking for, anyway?" she asked, patiently lifting her right arm when he told her to do so and then yelping in surprise as he pricked her finger and drew a blood sample.

"Sorry," he muttered, bringing the digit up to his lips for a quick kiss.

"Does that help?" Rose queried, raising an eyebrow at him and shifting up onto her elbows as he moved away.

"Yep," he replied absently, taking his glasses out and slipping them on as he stared at a monitor. "There are antibodies in my saliva that actually -" he trailed off and Rose sat up a little straighter at his unusual silence.

"Doctor, what is it?" Rose asked, swinging her legs off the side of the bed. He didn't respond, just muttered something to himself and tapped madly at another monitor. Rose frowned and crossed the room to stand beside him. "What?" she tried again.

The Doctor turned to her, his eyes wide, examining her once again like she was the most mysterious thing he'd ever seen in his thousand-plus years. She'd seen that expression now on three faces and it astounded her every time. "Rose, look at this," he said, indicating to the first screen. "What do you see?"

"A human DNA strand?" Rose answered, squinting at the screen, harkening back to her hazy secondary school biology days.

"Yes," the Doctor replied. "Yours, in fact, from when you first started travelling with me."

"You've got my DNA on file?" she asked, sounding surprised.

" 'Course I do," he scoffed, sounding distinctly Northern a moment. "Never had a companion who got into as much trouble as you. The TARDIS and I did a full work up on you right after you managed to get that sunburn on your first trip."

"Your fault," Rose sing-songed at him. "Someone decided taking me to see my planet get roasted would be an excellent first date."

He sniffed slightly. "Might of had a rather skewed sense of romance back then."

"Or no sense of romance back then," she laughed.

"Oi! I took you to an entire planet made of beautiful, sparkling ice waves," he retorted. "And I made you hot chocolate after that!"

"You're right, you did," she smiled back, leaning up to give him a quick peck on the cheek to mollify him, deciding not to remind him that Jack had actually made the hot chocolate. "Back to your mysterious monitors?"

"Right," he nodded. "This is an image of my TNA," the Doctor continued, pulling up another image, this time of a three stranded model. "The triple-helix is what allows Time Lords to regenerate among other - anyway, not important right now."

"Ok," Rose answered, slowly. "And?"

"And now," the Doctor said, turning the final monitor around to face her, "look at this."

Rose gasped, staring at the image on his monitor. It was another double-helixed sample but there was the beginning of third strand, which seemed to be constantly evolving, covering almost half of the structure. However, instead of being a similar colour to the other two, the new strand was a shining, dazzling gold, almost difficult to look at in its brilliance. It reminded Rose of something she couldn't quite place, something with of the tang of Time in the air and dust on the wind, something that echoed the words Bad Wolf to her. Shaking her head to clear it, she looked back over at the Doctor. She didn't need to ask, but he answered nonetheless. "Yours," he confirmed quietly.

"But, how - I don't, we, I was in here since Bad Wolf," Rose stammered, gesturing around at the MedBay. "That headache after New New York, bruises on my wrists from those manacles at Torchwood Manor, a scratch from that Krillitane, and on that space station -"

"Stop, Rose," the Doctor interrupted harshly and the pain in his voice kept Rose from retorting. "Let's skip over the listing of all the times I failed you over the last year we were together, shall we?"

"Doctor, that's not what I meant," she said, taking his hand and squeezing it.

He took a deep breath and then slowly exhaled through his nose. "I know," he answered, softly. "But believe me, I've relived every single one of those moments the last few years as well. Every bump, every scratch, every time I nearly lost you and the one time that I did. But you're right. We were in here, much more often than I would have liked, and these scanners never once showed me anything like that. To be honest Rose, I've never seen anything like it in my whole life."

"D'you think it's only been like that since I came back? I was in the MedBay with the last you right after I woke you up from your regeneration coma and you didn't say anything about it then, either."

"No, I don't think so," the Doctor answered, frowning slightly and letting go of Rose's hand to ruffle his hair. "It looks like it's been evolving for a while now. I do remember thinking that your scans didn't seem quite right back then but I was frantic with worry and more than a bit mad and the TARDIS wasn't being very helpful and - ooo. You. Oh, you tricky girl. This is all your doing isn't it?"

"Doctor?" Rose prodded as he stared up at the ceiling.

"You hid this from me, didn't you?" he continued out loud, sounding angry and confused. "Of course I didn't see it on the scanners because who controls my scanners? You do! But why? Why keep it a secret? If I'd known - oh, oh that's it, isn't it? Clever girl. If I'd known that there could have been a future for us like this, I would never have hesitated. Well, maybe I would have, but I'd have gotten over it. We could have bonded back then, don't you see, Rose?" The Doctor spun back toward her. "But…"

"If we'd bonded back then, your past couldn't have happened like it was supposed to," she finished for him as he walked closer to her, leaning in.

"Exactly! And your telepathy, Rose. She must have been keeping a tight lid on that too, communicating just enough to practice with you but not enough that I would notice. And then when we were separated, without her to keep it in control over in that parallel universe, it would have developed on its own, enough to fascinate my younger self but not enough to confuse or hurt you. Still doesn't quite explain the colours thing you talked about, or what, exactly, that gold stuff isbut we can study that more later..." he trailed off a moment, then grinning hugely, he picked her up and twirled her around, laughing. "Ha! I have the most brilliant timeship in the universe!"

"You have the only timeship in the universe," Rose giggled, sliding down his body and keeping her hands around his neck.

"True," he replied, snuggling down into her embrace and fitting his nose into the crook of her neck. "I also have the most brilliant Rose in the universe," the Doctor continued, making his little happy noise and pressing against her tightly, rhymically drawing her against him in a way that was just on the edge of erotic, especially as his right hand crept up her shirt and his thumb grazed her nipple. As Rose started to get mesmerized by the feel of his body against hers again and his lips against her neck, she saw his open book sitting on one of the exam beds.

"Ready to talk about the bond, then?" she asked, reluctantly reigning her hormones back in and pulling back slightly.

The Doctor looked a bit dazed for a moment, and then shook his head. "Right, bond. Right, I'll just, ah, go stand over there. On the other side of the breast. Bed! On the other side of the bed. Away from your breasts. YOU! Away from you. Not that I want to be away from you," he stammered quickly, even as he retreated. "Never. I never want to be away from you again. But, ah -"

"It's ok, Doctor," Rose laughed, wondering if his next body would act like a blushing virgin before they had sex for the first time, too. A brief flash of royal blue accompanied by a wave of heat and a fleeting thought of magic hands shot through her, gone before she could even process that it had been there at all.

He cleared his throat and tapped the book in front of him. "From what I can tell from this book, and there's not much there, this bond of ours is operating on two different levels," he began.

"Physical and emotional?" Rose asked, tilting her head to the side.

"Yes, actually," he replied, eyeing her oddly. "The physical aspects are part of a mating bond. I believe my eighth and ninth selves mentioned to you that part of Gallifreyan history, claiming and such. Time Lords supposedly put those urges aside a long, long time ago but I was always a bit of a rebel and they were always a bit of blowhards. And now that there aren't any others left…" he trailed. "It shouldn't have happened anyway, not with differences between our species and lifespans and mental acuity, but our lives are so tangled together, Rose, I don't even know where to begin. Everything about us seems to go in this complicated circle...and I'm not sure how it got that way."

"Did I do this?" Rose asked, quietly. "When I was Bad Wolf? I don't remember much but, if I had all that power…"

"I'm not sure, Rose," he answered, honestly. "But I could have done it as well...I held that power, too and all I could think about then was you. And the TARDIS...I'm not sure where she plays into all this. Maybe we all did it together. But it doesn't matter. We're here and I wouldn't change a single thing about any of this."

"Yeah?" Rose said, watching him carefully as he moved back to her, leaning up against the exam table and taking her hand.

"Yes," he replied. "I think the mating bond is a large part of what's driving this physical need. Practically all I can think about right now is throwing you down on this table and shagging you until neither one of us can stand." His eyes widened as that came pouring out. "See?" he said taking a deep breath and flushing brightly. "It wants to be completed and we haven't finished it yet."

"And the emotional part?" Rose asked, her own breathing a little ragged in the face of the heated look he was giving her.

"Walk with me?" the Doctor said, quietly, tugging gently on her hand and leading her out of the MedBay. They walked through the corridors until he led her out the doors of the TARDIS to the rocky, red wilderness outside. He led her over to large, flat rock and the two of them sat quietly another moment, watching the strange, flying inhabitants of the planet soar overhead. "Didn't want to talk about this in the MedBay. Too many bad memories. But I want to do this right. And right doesn't start with a frantic shag on an uncomfortable table."

"I read through that whole book, Rose, thinking that what I saw there couldn't possibly be right. A mating bond? A biological imperative? A useless reproductive urge from a bygone era? It didn't seem like enough. That's not us. I don't just want you physically, Rose. It's never just been that, as beautiful and wonderful and sexy as you are." He squeezed her hand and let his thumb caress her wrist, staring ahead.

"And then I saw a footnote, an asterisk down at the very bottom of a page, shoved away like it was something to be ashamed of, even more embarrassing than the physical urges the Time Lords tried so hard to pretend like they never had." He paused and took a deep breath, his large, dark eyes swing over to meet Rose's. "A mating bond backed with mutual feelings of dedication and respect and affection could be more, so much more, terrifyingly more. And that frightened them so much, Rose. It frightened me, too. They used a bunch of fancy, meaningless words, but in the end, it was about love."

Her breath caught in her chest and he shifted to one knee in front of her. "I'd like to say that I'm not scared anymore, Rose, but I am. I probably always will be. I'm scared of losing you and I'm scared of hurting you. I'm scared of how much power you have over me and what the universe might try to do to us because of it. But I'm not scared of loving you, not anymore." He stopped and took a deep breath, tears shining in his eyes and in hers.

"It's called a marriage bond, Rose. I've spent the last five years wishing and dreaming and regretting and I want to do this right, for you and for me. I love you, Rose Tyler, with all that I am, all that I was and all that I ever will be. Will you become my bondmate? My life partner? My wife?"

"Yes," she whispered and his answering smile lit up the landscape even as dusk began to fall around them. "Yes, absolutely, yes."

He leaned up and kissed her then, cradling her jaw in his hand. They certainly had a lot more to discuss and to plan and to prepare for, but for now, this was enough.