Rose doesn't need to ask where he is. No matter where he is in the TARDIS, his new found penchant for singing is sure to lead her to him. Accompanied or unaccompanied, his rich and often off-key notes permeate the air and carry down every corridor. And all without a microphone. If he wasn't such an early riser, she might even be impressed.

But as it is, it's six in the morning by her watch and last night was a heavy one. After sorting out a minor mishap on some distant planet, he'd decided it was as good a time as any to introduce her to the local cuisine.

"And when I say local, I mean alien," he'd elaborated, as they opened the door of the building he'd led her to. "And when I say cuisine, I mean drink."

As Rose buries her aching head under the pillow, she gives up even trying to remember how much she had last night. After the seventh glass, it's all a bit of a blur. But her sinking stomach suggests to her that something embarrassing happened last night. Her foggy brain tries to sort through what she can remember.

Then he starts again, and he sounds like he's right outside her door. Cheerfully bashing his way through the collected works of Bon Jovi and Oasis, sometimes forgetting the words and making them up as he goes along. She usually forgives him for that though; at nine hundred years old, he's seen and heard enough music to make a few slips of the tongue inevitable. Anyway, he does do it brilliantly.

But it's six in the morning and they didn't get to sleep until two at least; Rose vaguely remembers seeing the time on the alarm clock by her bed before her head hit the pillow and she slept the deep dreamless sleep of the completely inebriated. Of all the times in the world for him to test out his baritone, this is not the best. With a groan, Rose tries to push the pillow harder down upon herself, to muffle his voice. She's definitely running the risk of some minor smothering, but it would be worth it if she could just block out that noise and go back to sleep until at least twelve o'clock. And then in an ideal world, a full English breakfast, with bacon, sausage, fried bread, beans and endless rounds of toast would appear by her side.

As if he knows she's trying to ignore him, his voice gets ever louder. He's reaching his favourite part of Livin on a Prayer, the key change. It makes Rose's ears ache even when her head isn't thudding like a baby elephant, no, make that a bull elephant is charging around behind her eyes. She knows she just can't take it this morning. Her head swims as she launches herself out of bed, realising as she gets halfway to the door that she was too out of it to even get changed for bed properly last night. She obviously thought sleeping in her underwear was perfectly acceptable. She hesitates for a second, but she can hear him making guitar noises, and can imagine him warming up for his prized moment. Grabbing her waffle dressing gown from where it was thrown in the doorway when she had a shower yesterday morning, she opens the door just in time to prevent the inevitable.

"Please!" she whines, as anything above the smallest whimper makes her stomach lurch. "Please, stop."

He turns round and she sees him take in the picture before him. Taken aback for a second, his eyes travel the length of her body, before he remembers himself. Even so, she gives him a dirty look and pulls her dressing gown on roughly.

He shakes himself. "Sorry, did I wake you up?"

"It's six in the morning." Rose's voice is husky and she can smell smoke in her hair. Even on those far away planets, they still enjoy a quick puff or two when they go out. Still, at least the TARDIS has some sympathy for her, dimming the lights for her.

"Oh, I suppose it is." He nods. To her utter disgust, he's already dressed and looks perfectly normal. Maybe even better than normal. She swears she can see a more than normal glow to his cheeks and he seems bouncier than normal. These late nights really seem to agree with him.

"But the acoustics are really good down this corridor," he continues enthusiastically. "People would pay good money for acoustics like this, Rose, believe me. You try, even your voice would sound good down here."

Rose glowers at him, wondering if strangling him would cause her head to throb any harder.

"You're… you're not looking to good this morning," he says finally, a little unsure of himself. "Are you feeling all right?"

Determined not to appear weak in front of him, and risk another hour's lecture on the inferiority of the human species, Rose forces her voice to appear more normal, and persuades a smile onto her face. The elephant immediately starts digging his tusks in behind her eye sockets, but she battles on nevertheless.

"No, I'm fine," she says, over brightly. "Just fine."

"Good good." He grins cheerfully, before sauntering off again, hands in pockets, whistling. Any minute now he'll start singing again, she knows he will. He can't help it. "I'll see you in a bit then," he calls back, and she has to admit, the acoustics are pretty good.

She stumbles back into her room and flops head first back onto her bed, waffle gown and all. She buries her head in her duvet, trying to make the pain go away by the power of positive thought. But she can hear him singing again, and she contemplates murder instead. He never used to sing…

Suddenly she forgets her headache, her mind throwing up a million and one other thoughts. Her brain's too busy to even consider dying.

He sings. He sings now.

She's noticed lots of little quirks of his that have replaced the old ones. The way he has his tea. His head scratching. The way he always puts on his left shoe first, whilst the old him did the exact opposite. She can't believe she's missed this one. He sings now. He never used to, she can't remember ever hearing him utter a note. Dancing, yes, he loved dancing, he was good at dancing. She smiles suddenly at the memory, remembering how he… But that's beside the point. He never sang, not even in the shower, not even ironically to one of her CDs, though he was always quick enough to pass judgement on her voice. Now he won't shut up singing: in the shower, in the bath, in the kitchen, at the most inappropriate times. But he isn't the one who sang to the Daleks…

Her hangover momentarily forgotten, though he's still wobbly on her feet, Rose heads down the corridor, intent on finding him and telling him this. Because something she's known for a long time, something that she's wondered and pushed to the back of her mind again and again, has finally forced her into action. This time she needs to know what happened.

He glances up from where he's staring at the screen on the control panel. A smile breaks across his face, and Rose pauses for a second to let it's warmth wash over her. But she's not here to bask in his smiles; she needs answers.

"Not getting dressed today?" he teases before she can quite form the words she needs. That's something that hasn't changed, his insistence of always getting the first and last words in.

But she's not far behind. "You sing," she says, and realises as soon as the words leave her mouth that her argument isn't quite fully formulated yet. But even so, at least she's on the way to something now.

He frowns, a little confused. "Um, yes, we've established that," he says. "And I'm sorry for waking you up. I've stopped now, so-"

"No," Rose interrupts him. "I mean, you sing now. This you, the second you… you sing."

"And?"

"The old you didn't. Not ever."

He shrugs. "Well, you know… new new Doctor and all that." He flashes her a cheesey grin. "All new and improved better model, complete with, even though I say it myself, a fine set of vocal cords."

Rose shakes her head again. "You're missing the point. You never used to sing."

"Well like I said-"

Rose is starting to get the hang of this interrupting thing. Maybe he's right, being rude is sometimes the best way. "But you sang to the Daleks."

And then she knows she's got him. For the first time she sees a flash of pure terror pass over his face and the smile disappears.

"I did?" he fakes ignorance. "Oh, that was right before I regenerated, Rose, I can barely remember that."

"You said you sang a song and they ran away." Rose is appalled at how naïve she was at the time; it would take more than a bit of rusty singing to scare those killing machines away.

"Well. There you are then." He's speaking in clipped tones, a sure sign he's hiding something. "I was probably so awful back then that it frightened them half to death."

"But I heard it. The singing. It was beautiful." Rose can remember the haunting melodies and strange unearthly voices. It feels like they're inside her head. It had been so beautiful it had made her want to cry. Thinking back now, she wonders if she did. And it had hurt, she can remember pain.

"Pre-regeneration, maybe it was the new me coming through." He's running out of excuses, his voice is getting increasingly high-pitched. "Bit of a mix up of things, you know."

But she's sure it wasn't that. "It didn't sound like you. It was…" She knows she's heard it before then, heard it since. It feels like it's always been around her, in the background, so quiet she's never noticed it properly. She can remember how it all felt at the time, clearer than ever before. It felt like being curled up in a warm bed with someone you love. It felt like standing on a precipice, with nothing to hold on to. It felt like a warm summer sun beating down upon you from above. It felt like falling down and down into a cold abyss. And she's feeling it again, more every moment, like the tide rolling in over her, drowning her in the feeling.

"Rose, it doesn't matter, it's gone, it's over," he says, desperately, urgently, like he can see it all happening to her and wants to stop it. "Don't think about it anymore."

"But you didn't sing," Rose says again, her brain hurting with the wealth of thoughts and ideas crowding into it. And yet it's all seeming so clear to her now, that he didn't sing, that something else happened, that… she happened.

"No, I know, I-"

"Then what did happen?" She fixes him with a level stare. She's not to be messed with this time, she needs to know. It's time he told her the truth.

The Doctor meets her eye and she sees him realise it's time. Time he stopped hiding the truth from her about who he is, who she is. Time he let go enough to share it with her.

He takes her hands gently and guides her into the chair by the console panel. She's sat here so many times, watching him work. She sometimes brings a book, and they both sit in companiable silence, as he tinkers away with various levers, and she immerses herself in an eighteenth century romance. Sometimes they talk as he works, her book momentarily forgotten as they discuss wordly matters, or share life experiences. Sometimes she just sits and thinks, a smile breaking across each of their faces when their eyes meet. But this time she knows it'll be different.

He leans against the control panel awkwardly. He's slightly taller this time around and it's not quite the right level to accommodate his bony limbs. But even as he wriggles trying to get comfortable, he keeps hold of her hands. She's glad, because she can feel her fingers trembling. Then she realises that he is too.

"You're right," he says finally. "I didn't sing." He pauses for a long time, as though he can't think how to say it. The Doctor, the man of a million words, a trillion, and he can't find a way to tell her the truth. She begins to wonder if she really wants to know, but it's too late now even if she doesn't.

"I could have sung," he says. "There is supposed to be an old Time Lord song that Daleks turn to dust at but I never learnt it. And I didn't need it anyway. Rose.." He swallows hard. "Rose, I didn't need to sing. Because I didn't save the universe. The Bad Wolf did."

Bad Wolf. The images rush through Rose's mind so fast they make her feel nauseous and she would have fainted if she weren't sitting in the chair with the Doctor holding her hands tightly. Those words that followed them all over the place for so long, appearing in the past and the future and leading them to their fate. I am the Bad Wolf.

He's still trying to explain it to her. "The Bad Wolf was… The person who saved me was…"

She finally speaks, her voice barely above a whisper. "Me?" she asks hesitantly, still unsure of herself. She feels it must be true, there's no other answer for it. "I saved you?"

He meets her eye again and she notices the tears in them, glistening so faintly. And he nods. "You. You, Rose."

"I… I saved… you?"

"Yes, Rose! Oh yes!" He pulls her to her feet suddenly, and puts his hands on her shoulders. His hold is firm but so gentle that she can't object. He looks up to the ceiling and blinks away tears. "Oh, Rose, you saved me and everyone up there," he says softly, his voice soothing some of the pain in her head away. "You came back, Rose. You… You came back for me."

Rose nods, everything making sense for the first time in a long while. "I had to, I had to find you and keep you safe." She shakes her head. "But I don't remember… How? What did I do?"

"You looked into the time vortex," he tells her. "The heart of the TARDIS? Remember when Margaret Slitheen did that?"

Rose nods again, tears spilling down her face. "But you said you did that. You said that was why you regenerated, that no one should do that, that it was killing you. Why didn't it kill me?"

"Because I took it off you, Rose."

"What…?" She frowns. "But how?"

He looks pained and she wishes she could let him be, let this be over with. But she needs to know.

"I… I kissed you. I kissed you and took the vortex away from you and put it back where it belonged. Here." He pats the TARDIS. "You'd done what you had to do with it, Rose, you didn't need it anymore. Rose! I'm sorry, I couldn't let you keep it!" He speaks quickly as he sees tears falling down her face.

But it isn't that that's upsetting her. She's not interested in the power she might have had, destroying a whole fleet of Dalek ships and their crew. She only cares about what she did… because she killed him. Her Doctor, the man she loved. She tried to save him and only succeeded in destroying him anyway.

He puts his hand against her cheek suddenly and raises her face up to look at him. And he's smiling softly.

"No, Rose," he speaks just as gently. "You didn't kill me. I was at the end up there anyway, if you hadn't have come back for me… I'd never have released that wave. It would have been over. For everyone. But you did it, Rose, you saved them all. Me and everyone in the universe."

She sniffs hard. She doesn't question how he knew what she was thinking. She's always felt the TARDIS in her mind, and she knows why now. "It wasn't the universe I cared about," she says quietly.

He bends his head down inches from her, until she can count every faint freckle on his cheeks and feel his hair tickle her forehead. "I know," he says almost without any sound at all. "I know. Thank you, Rose Tyler. Thank you for this." He gestures to his new body with a tiny tilt of his head

Rose smiles. "You're welcome. Anytime," she says.

Then he pulls her into a tight hug, letting her bury her tear-stained face in his suit. He holds her close, and she gradually finds herself breathing easily again. She's the Bad Wolf. But she can cope with that. She did what she had to do and saved who she had to save. And she's so glad she did.

Finally they break apart and she realises that she's still only got her waffle-weave dressing gown on and that the belt fell off a while ago. It's fallen open to show her underwear off again. She pulls it around herself, blushing.

"Oh come on, Rose," he teases. "Surely the Bad Wolf doesn't blush."

She smiles. "When she's practically naked she does." She steps backwards. "I'm going to take a shower I think. And then a bacon sandwich wouldn't go amiss."

"With extra grease?"

"Always." She remembers something else she needs to ask. "Last night. What exactly happened?"

"Oh, the usual." He puts a hand in his pocket. "We had a few drinks. A lot of drinks actually. Then we…" He smiles.

"We what?" Rose feels her heart jump in her chest.

"We went to a karaoke bar." He grins.

Rose tries not to appear disappointed. "Oh. Right. What did we sing?"

"Well, I sang my personal favourite, of course-"

"Live Forever," Rose finishes for him, with a small smile.

"Yep!" He grins again. "And I seem to remember you giving a pretty crowd-raising rendition of Lady Marmalade."

"Oh, you're joking?" Rose groans. "Is that the end? Please say that was it."

"Then we sang a duet."

"Of what?"

He pretends to think until he catches Rose's death-glare, inherited from her mother and honed to perfection. "I'm fairly sure it was Elton John and KiKi Dee, Don't go breaking my heart." He pauses before adding, "And you did Elton's bits."

Rose pulls a face. "Okay. Is that it? I didn't dance on tables or kiss some alien or challenge anyone to a drinking competition?"

"Apart from your interesting musical tastes, you were the model of perfection," he replies.

She breathes a sigh of relief. Karaoke. She can deal with that.

"Good. Right, shower it is then. And then I want that sandwich!"

He gives her a mock salute as she walks off down the hall. He turns back to the screen on the console to finish what he was doing. He smiles as he remembers winning every drinking game she challenged him to last night. He smiles as he remembers how she wobbled off the table in those stupid heels of hers and only avoided serious injury by landing in one very excited man's lap.

And as he walks down the corridor to the kitchen to start frying the bacon, he smiles as he remembers the feel of her lips on his as they walked back to the TARDIS. Right before she passed out and he had to carry her home and put her to bed.