In this chapter I explain about Jenny - it's obviously going to be slightly AU, because this isn't how things happened in the actual episode. The eagle-eyed amongst you will also have noticed a lack of Tentoo, also slightly AU.

"What? Wh—wh—how did this happen? Who—I mean, what the—"

Rose stuttered to a stop, like a car that had completely run out of petrol. She had absolutely nothing left to say that would not have just come out as a confused squeak.

"No no, wait." The Doctor held up a hand to try and stop her whirling thoughts, the other curled securely around the little girl – Jenny, had he called her? "Before you say anything, I did not plan this and there was no-one else involved. There hasn't... I mean, there wasn't anyone else." He seemed desperate for her to know, eyes almost pleading. "Come on, I'm a 900 year old alien who's the last of his species, I spend a lot of time moping. Poor Martha got the brunt of it; I'm surprised she actually survived. It's going to take more than a couple of years before I can move on from being separated from the woman I love." He scrunched his eyes shut in embarrassment for a moment, trying to ignore Rose's raised eyebrow and knowing smile. "Yeah. Whatever, the point is, Jenny was created from a machine."

He gingerly sat down next to Rose on the sofa, trying not to do anything to wake up his daughter, and told Rose the story of how he had ended up a father again, something that he had never intended to happen. "It was this machine that extrapolates DNA and uses it to create an offspring of that person, who is genetically mother and father to the child." Rose nodded, her gaze flickering between him and Jenny, cataloguing the similarities in their faces even as she listened. "The products of the machine were intended to fight in a war – which we stopped, as we often tend to do – so they are normally created as fully grown adults. But something in the Time Lord DNA made the machine malfunction, so Jenny came out as a baby rather than a fully grown adult. "

"I bet that wasn't helpful," Rose said quietly.

The Doctor pulled a face. "No it was not. Me, Donna and Martha were trying to stop war from breaking out, and suddenly I have a baby, who I am struggling to accept is my daughter, to cart around with me. She was spectacularly unhelpful," he said fondly, looking down at Jenny's head and stroking her hair softly. Rose felt a strange mix of emotions swirl around in her stomach at the sight of the Doctor being so utterly calm and confident with Jenny – confusion, pride, a little bit of longing (if she was honest with herself.) Despite him having been a father before, she still sort of saw him as an over-excitable idiot who loved adventuring and doing dangerous things with no back-up plan. If she hadn't seen it with her own eyes, she would not have believed that this was happening.

"Me and Donna managed to look after her for a couple of months – she was about 16 months or so when she was created, and she seems to be aging at a normal rate, though this situation isn't exactly common so I really don't know what to expect. It's meant less adventuring, and it's a good thing I don't need much sleep, she did not like sleeping in the TARDIS at first – but when the stars started to go out I took her to the one person I trusted most."

He stopped, and Rose searched her brain, realising she had a pretty good idea of who it was he was referring to. "Sarah-Jane," she said.

"Exactly!" The Doctor grinned. "I knew Jenny would be safe with her. I know," he said before Rose interrupted him, "Sarah-Jane was there today on the Dalek Crucible, but she left Jenny with her son Luke, who looked after her fine while everything else was going on. Brilliant boy, definitely gonna call on him again if I need a babysitter."

"Wouldn't it have been safer to leave her somewhere that wasn't under threat from Daleks?"

The Doctor paused. "Well yes, but I wasn't really thinking straight, in case you hadn't noticed. I was a little bit distracted by a certain message from a certain someone." He elbowed her and Rose elbowed him back. Everything felt familiar and strange all at once, so surreal that Rose was half convinced she was in a dream.

Jenny began to stir, and the Doctor looked down at her. "Would you like to meet her?" he asked Rose, who nodded her head eagerly. As Jenny was waking up, Rose caught a little worry and uncertainty in the Doctor's eyes – a flash of something that clearly stated that he was not as at ease with this situation as he pretended to be.

Rose watched as Jenny opened her eyes and looked around sleepily. She caught sight of Rose and immediately buried her face in the Doctor's chest, peeking out with one eye.

"It's OK," the Doctor murmured softly, kissing the top of her head. "This is someone I've wanted you to meet for a long time. She's coming to live in the TARDIS with us. Her name is Rose."

Rose gave a little wave and said "Hi Jenny," as unthreateningly as she could. The little girl was still clinging to the Doctor fiercely, but she managed a couple of seconds of eye contact.

"Are you going to say hello?" The Doctor asked Jenny, peering down at her face and smiling. There was long pause, and then, very quietly:

"Hi."

"Well done!" The Doctor sounded so pleased, and he gave Jenny a quick hug before lowering her down to the floor. She clung to one of his skinny knees, tiny hands fisted in the pinstriped fabric. "Can you say Rose?"

Another long pause, as if for dramatic effect.

"Wose." Rose felt a twinge at the remembrance of her little brother Tony calling her that. The ability to say the letter 'r' had come to him in the end, but it had not been too long after that that Rose had left that universe, never to return. She felt tears in her eyes, and struggled to hold them there rather than letting the Doctor see how much she hurt. There was plenty of time for pain and tears. Right now was about life and new beginnings and hope. She could not bear to bring the Doctor down while he was sharing something so special with her.

Jenny had taken off around the room, clearly a little wary of Rose but still eager to explore – just like her father. She made several attempts to climb onto the settee opposite them, managing it eventually and looking mighty pleased with herself at her accomplishment. The Doctor watched her with pride and amusement, but also a touch of wonder on his face. It was as if he could not quite believe that Jenny was real, and Rose knew the feeling. She was getting it right now as she looked at the Doctor.

The object of Rose's scrutiny laughed as Jenny slid down extremely inelegantly from the settee, laughing even more at Rose's wince when the reckless toddler nearly went flat on her face. "She'll be OK," he told her, "she'll just get up and carry on again."

Jenny span around before looking at the Doctor and giving him the biggest beaming smile her little face could manage. "Daddy!" she shouted, and she ran at him on slightly unsteady legs that were still half asleep. The Doctor bent down and scooped her up, lifting her high in the air while she giggled and squealed "More! More!"

It was just so odd to see the Doctor doing this. Seeing him as a dad was going to take some getting used to.

With them next to each other, Rose was able to really see the similarities in their faces. The big, brown eyes, the bottom lip that stuck out slightly, the hair that, although a different colour, was uncontrollable and somehow gravity defying. There was no doubt at all that she really was his daughter.

They played together for a little while, Rose mostly watching rather than joining in. The shock of the big reveal was wearing off, and the tiredness was beginning to reassert itself. After she had yawned widely about 4 times, the Doctor said with a smile that maybe she should go and get some sleep.

Rose had to agree with him, and was up on her feet and halfway to the door before she stopped and turned around. "Is my room still...?"

"Oh yes, it's still there." The Doctor was holding Jenny on his lap – she was, like Rose, also showing signs of weariness now. "Just where you left it. Shouldn't have changed much either, I imagine."

He held up Jenny's hand and waved it as a goodbye, and Rose waved back before leaving the room and closing the door softly. Outside the door, she shook her head a little, and gave herself a slight pinch on her arm. Nope, not a dream then.

After walking down the corridor for a few seconds, Rose came to a turning she recognised, and just around the corner she found the door to her room. It had some Gallifreyan writing on it that had never translated, which she had always assumed meant 'Rose's Room', but she was never sure if that was really what it said. She pushed the door open and smiled.

It was her room. The feeling of coming home intensified at the sight of the pink sheets and the soft carpet and the door to the ensuite that the TARDIS had put in after Rose had gotten lost looking for a bathroom on her first night. There were subtle differences though, if you knew where to look, and Rose did.

All the colours were slightly more muted, which made the room feel a little more cool and calm that it had done – she was grateful for it after the mad day she had just been through. It was tidier than she had left it too, books neatly stacked and bed made. There were fewer clothes than she used to have – Rose remembered that she had taken a load home for her mum to wash on the day that she had been in the TARDIS for the last time.

The pictures were still there too – snapshots of her life with the Doctor, mostly awful and out of focus from being taken on her rubbish phone, but they were reminders of the life that she used to have. She examined each one closely, smiling and reliving the memories with the thought that she could now make some more. She stopped, that thought glitching in her mind. Would they be able to make more memories like this? The Doctor had a child now; he couldn't be running off into danger all the time. Maybe they would have to make different sorts of memories now.

Rose shrugged off that thought, pushing it to the back of her mind for contemplation at a later date, before pulling off her clothes and flopping into bed in just her knickers. She was under the duvet and asleep in seconds, the TARDIS humming and moving some clothes from the enormous wardrobe room to the modest sized wardrobe across from Rose's bed, so her poor human wouldn't have to go searching for any more when she woke up.