Sorry I've been so long getting this uploaded! My life has been full of plot twists lately. However, I refuse to let that get in the way of me eventually completing this story. Here's chapter four; let me know if you have any characters/ideas you'd like to see incorporated. I've got a vague plot formed in my head, but nothing is set in stone. Enjoy!

Rose

"You mean this is him?" Jackie said skeptically, looking back and forth between the two Doctors.

"Yes, mum, he's regenerated again."

Her gaze fell on the new Doctor and she studied him closely. Rose's dad was dumbfounded, still not an expert on the concept of regeneration. "Let me get this straight," he said, his brow furrowed. "This is him, the real one- no offense intended, Doctor-"

"None taken," replied the human Doctor courteously.

"-But he's changed into a completely new person."

"Right."

Pete paced to the other end of the sitting room and back, his hands in his pockets. "Okay, I've seen stranger," he admitted, returning his thoughtful stare to the bow-tied Time Lord. "Just answer me this one question: How exactly did you get here?"

"That's right," Jackie murmured, as though it were occurring to her for the first time, too. "I thought the- the thing between the two worlds was gone. How'd you cross it, then?"

The Doctor shrugged. "It's impossible. It shouldn't have happened, but it did."

Rose's mum clearly wasn't satisfied. "But if it's impossible, it's impossible!"

The human Doctor spoke up. "They say that a lot of things are impossible, but if you haven't been paying attention, look around yourself." He held his arms out to indicate their surroundings. "We're in a house owned by a man who, in one version of reality, is dead. He's married to a woman who, in this reality, is also dead. They have two children, who, genetically, are brother and sister, but are technically only half-siblings." He pointed to himself. "Your daughter is married to a man made out of a hand! If any if this isn't 'impossible', I don't know what is."

Rose took his arm gently and addressed her mother. "Just take it for what it is, mum."

The Doctor (the real one, according to Pete) took a step forward. "What he– or well, what I am trying to say is that every rule has its exceptions, and that's what this is." Everyone was listening intently. "Impossible possibilities, if you will."

There was a moment of brief silence following this statement, broken by Rose, to whom a thought had just occurred. "Doctor," she began, addressing the Time Lord gently but with a trace of concern in her voice. "You may have gotten here just fine, but how is it you're planning on getting back?"

"Ah," he said, an odd sort of smile playing on his lips. "Here's the thing, see: I haven't the faintest idea."

Ten minutes later, they had all gone back to the Tardis and now both Doctors were engaged in an intense discussion. Rose, Jackie, Pete, and a bewildered little Tony were standing in the middle of the control room, talking amongst themselves.

"Mummy," said the child, tugging on the hem of Jackie's shirt. "Mummy, why is it smaller on the outside?"

The bow-tie-wearing Doctor broke his concentration for a moment, found Tony's wide eyes from across the room, and said, "Don't be ridiculous, Anthony. It isn't smaller on the outside." The boy's brow furrowed at this, causing the Doctor to smile and say, "It's bigger on the inside."

With this explanation, the two Doctors resumed their hushed conversation. Rose sighed as she looked at this stranger and her husband. It was difficult to remember that they were the both the same man; they were so very different.

She wondered, then, what the Doctor had been doing since they had last met. How long had it been for him? Had he regenerated just once, or was this his twelfth or thirteenth reincarnation? That would explain the difference between the two. Rose considered how extremely old he must be. Had he reached one-thousand yet? What had given him the deeply saddened eyes, the slight heaviness in his gait?

Still, for some reason, the question that plagued her most was whether or not he'd found someone else to take her place. Rose recalled Donna Noble. What had become of her? Had he replaced her, too, the same as he'd done with Rose when she was gone? What pretty girl had been traveling with the Doctor most recently?

She knew it was silly, but she wondered if he'd ever fallen in love again. The thought both hurt and confused her. Watching her human husband, his wild hair, the sharp features and impossibly ancient eyes that she knew by heart, she couldn't imagine loving him more. Could she blame his original self for seeking someone else?

Rose's thoughts were interrupted by Tony's small hand poking into her thigh. "Rosie?" She looked down at him, smiled and scooped him up into her arms, planting a small kiss on his forehead. This entire ordeal would be overwhelming for her brother, she thought. He'd finally entered the magical world his family had always told him of.

She easily remembered her first time stepping into the Tardis. She'd been nineteen years old, freshly unemployed, and strangely entranced by this mysterious Doctor fellow. A small smile pulled at her lips as she recalled the living plastic version of her then boyfriend, Mickey Smith, pounding on a metal door that led to where she and the Doctor were standing. When he was about to break through, the Doctor had urged her to enter his Police Box, and Rose, seeing no other alternative, had done so. Upon one glance inside, she'd pulled back in amazement, running back out and inspecting the blue box from the outside. Sure enough, though, it was no trick or optical illusion; it really was bigger on the inside. The sheer shock of that revelation had led her to one conclusion: the Doctor was from another world. She'd gone inside and asked him directly if he was alien, to which he'd simply replied, "Yes."

It was, perhaps, the easiest response to a question she'd ever received from the Doctor.

"Right, then," her one-hearted Doctor said, raising his voice to address the entire group. "My– er, learned colleague and I have come up with three possible explanations for all of this."

His two-hearted counterpart, though looking a bit disgruntled, continued. "One: this is all a dream state intentionally brought on by the Tardis to distract from… other things."

"Not likely," remarked Rose, setting her brother back down. "If it is, then I'm having the same dream."

"Which is exactly what I would expect you to say," the Doctor pointed out. "Next, there's always the theory that when I left here the last time, I didn't close the gap completely. Also unlikely, but mistakes do happen."

Rose recalled the "last time," when she'd barely gotten a chance to say goodbye. It still hurt to think about, even with the Doctor back.

"The last idea," he began, pacing and adjusting his bow-tie. "Is that the universe you've been living in since I crashed here is actually an offshoot of your parallel world. That would mean that in getting here, I accidentally created a second version of your universe."

Rose's head pounded with this thought. "You mean there could be another version of us right now," she gestured to her family. "Sitting around a table and eating dinner without meeting you?"

The Time Lord nodded. "And that's the only difference. Everyone else would be doing the exact same thing either way, but I've come in and changed your evening completely, haven't I?"

"Doctor?" Rose's dad interrupted. When both men turned to face him expectantly, he added, "John, I mean. Good God, this is confusing." He blinked fiercely several times before addressing his son-in-law. "Anyhow, John, which answer do you think is most likely?"

Rose's Doctor walked towards them slowly. "I'm not certain."

"Then how can he get back?" Pete asked, gesturing to the other Doctor, who now leaned against the Tardis's central control panel.

"We have to try to find a solution for all three theories," said the Doctor, taking hold of Rose's hand. Her heart beat faster for just a moment and she marveled at the fact that her husband's touch could still make her so giddy.

"We?" Jackie asked, repeating the Doctor's word.

Rose's Doctor smiled. "We."

"Right," the Time Lord Doctor chimed in, walking over to join the others. He knelt before Tony and smiled. "Young man, how would you like to travel in time?"