"Rose Tyler!"

Rose jumped in shock as the Doctor stormed into the kitchen, his suit jacket flowing behind him, looking like a batman cape.

Rose had a very odd image of the Doctor as a superhero complete with underpants on the outside of his trousers. She shook her head to get rid of the disturbing image.

"What?"

She was baffled as to what she could have possibly done to make him yell her name like that. It wasn't like she'd been painting her nails on the console again.

"This!" He held out his finger and thumb.

She blinked. "You've stuck your fingers together with the sonic screwdriver again? I told you setting 911/999 was just asking for trouble."

"No!" He frowned, although there was a slight blush to his cheeks as he recalled the incident. "Look!"

Rose was none the wiser. "What?"

He came closer and held his finger and thumb right under her nose. "See, here, look."

She peered down. "Is that—?"

"A grey hair!" His astonishment was apparent as he exclaimed loudly. "I have a grey hair!"

Rose's lips twitched. "Seriously?"

"Well, not any more," he added fairly, "since I just pulled it out. But look, look at it. Its just there all grey and forebode-y. Foreboding."

Rose folded her arms. "It's just a grey hair and you'd be due for one, ya know, being ancient."

"Oi!" He pointed at her, his eyes wide. "I'll have you know that this body isn't even one Earth year old yet!"

Rose wrinkled her nose as she thought about that. He had a point; it had only been about ten months since he had regenerated so this body was still almost toddler-ish.

That would explain his temper tantrums and the odd penchant he had for sticking things in his mouth.

She hid a grin.

"They do say that grey hair is a sign of wisdom," he mused, head on the side as he regarded the offending hair.

"Yeah, but the ones who say that are all old," Rose added.

"Thank you very much, Rose Tyler." He couldn't seem to get over it as he peered down at the offending hair again.

"Surely it's not that much of a shock," Rose sadi, sliding over to watch him. "I mean, ten bodies, yeah, must have been grey at some point."

"Yes, yes," he dismissed. "White, black, silver, chestnut, blond, curly, short, girly, even shorter and manly, but going grey? Don't remember actually going grey before."

Rose grinned. "Well, look on the bright side. You're almost 900; with grey hair at least you'll look it."

"That's not funny."

"Sorry, Grandad."

"I've always preferred Grandfather. Sounds more distinguished somehow."

Rose paused. He'd told her that he'd had children, but the thought of his having grandchildren was a bit odd. "Grandfather?"

"Yes, Susan?" He said absently, still staring at the hair.

Rose blinked. Susan?

"Susan?"

"Hmm?" The Doctor seemed to come back to himself and peered at her. "What?"

"You just called me Susan."

"Did not." He blustered.

"Yeah, ya did. Who's Susan?"

"My granddaughter." He put his hands in his pockets and rocked back on his heels, watching her closely. "Susan Foreman."

Rose didn't know what to say to that. How do you react when your friend mentions, for the first time, his grandchild. His previous self would never have mentioned his family and she wasn't sure whether she was supposed to just accept the tidbit of information that he had let slip about himself or if she was supposed to question him further.

"What colour hair did she have?"

Rose wanted to slap herself for the inanity of the question but the Doctor grinned and, somehow, as was often the case wit the Doctor, without quite knowing how, Rose had asked the right question.

"Dark, very dark, almost black. She could be a right handful—like you."

"I remind you of your granddaughter?" Rose replied, unable to keep the horror out of her voice.

The Doctor's eyes widened. "No, no, no. God, no. Ew."

"Ew?" Rose shook her head. "No more American shows for you."

"I was just saying that there is no resemblance between you and Susan other than the fact that you are a magnet for trouble."

"Oh," Rose gave him her most innocent smile. "Maybe it's you, I mean maybe you can't keep up anymore. Grey hair, gammy joints."

His eyes crinkled. "Oi, enough of that."

"Perhaps we should make our next point of call Mablethorpe, or Skegness."

"I'm warning you!" he said, a laugh in his voice as he advanced on her. Rose slipped off her chair and darted around the table.

"How about Brighton? I hear they do great deals for OAP's. Bingo night'd be just your thing."

He sprinted around the table but Rose was quicker. She gave a laugh and had the table between them again. "Poor old Doctor, gotta swap the TARDIS for a Zimmer frame."

He tried to dive over the table but she'd headed for the door, pausing as she reached it.

"I'll get you a bumper sticker "I'm so old I've had to change my sonic screwdriver for a hearing aid." You can stick it on the TARDIS."

"I'll tell you where you can stick it, minx!" he challenged and raced for her.

Rose turned and hurtled down the hall, laughter ringing throughout the machine.

She dodged around the TARDIS console in the control room.

"Not as quick as we were, are we? Need a hand?"

"Depends where you're gonna put it."

Rose froze at the innuendo in his voice. "A-aren't you a bit old for that," she managed to keep the teasing tone but the slow smile that edged over the Doctor's face was nothing short of seductive.

"Oh, you're as old as you feel."

She swallowed, not really knowing how the conversation had changed from one kind of teasing to the other. "And how old do you feel?"

He edged around the console. "When I get hold of you, Rose Tyler, I'll show you exactly how old I feel."

Rose's breath caught and her heartbeat thundered at the devilish look in his eyes.

"Promises, promises," she said and let herself be caught.