A/N: Hello and welcome! Like many of my stories, I have a whole saga planned out for this, that will include Ten, Clara, Rose, Jack, Jenny, Donna, Strax, Torchwood 3, and tons of others, but we'll see how far I make it! Your support and reviews are always needed and welcomed. Thank you so much for reading this story, and shoot me a PM with any questions you may have!

Disclaimer: I stink at disclaimers. Mine will all be boring. I don't own Doctor Who. There, happy? ;P

~Marina

Change

"Go on, then," the Doctor grinned openly at Rose, fully expecting her to roll with his unexpected change, "Tell me. What do I look like?"

Miss Tyler, however, was still partially hidden behind one of the Tardis' coral beams and watching the skinny man with crazy, long hair in her Doctor's jacket like he was a nutter off the streets.

Which, to be honest, he probably looked like, but she could still be a little more accepting, right?

"Who are you?" her voice wavered uncertainly.

He decided not to let it faze him, though he was a little surprised. "I'm the Doctor!" he reassured her, the smile dropping from his cheery-looking face.

"No—where is he?" Rose asked, still staring at him in wide-eyed shock. "Where's the Doctor? What have you done to him?" she continued more forcefully, stepping out to face him.

He gave her a confused look. "You saw me; I changed! Right in front of you." Had she closed her eyes or something?

Rose lowered her eyes. "I saw him sort of—explode—and then, you replaced him, like some sort of teleport, or a transmat, or—a body swap, or something."

She approached him slowly, and sped up a few steps with a look of determination before reaching up and shoving him slightly backward.

His new muscles kicked into gear as he kept his balance and rocked back forward onto the balls of his feet again. Watching Rose carefully with a frown on his brand-new face, he wished she'd just get it and move on. They had so much to do! They were on their way to Barcelona, for crying out loud!

"You're not fooling me!" she exclaimed suddenly, with a little sniff. "I've seen all sorts of things. Nanogenes—Gelf," she paused for effect. "—Slitheen."

He raised his eyebrows, truly amazed that she could be this naïve.

"Are you a Slitheen?!" she suddenly exclaimed.

If she wasn't so serious, he could have laughed. A Slitheen would have never fit inside this lanky new body of his! "I'm—not—a Slitheen," he replied slowly.

"Send him back," Rose demanded, backing away from him again. "I'm warning you; send the Doctor back, right now!"

"Rose, it's me!" he protested gently, determined to convince her. "It's—honestly, it's me!" He stood up a little straighter. He fell taller, looking down at her now. Must be about six foot three. "I was dying," he explained more carefully. "To save my own life I changed my body. Every single cell, but," he shrugged, "it's still me."

Rose started shaking her head. "But, you can't be!" she barely whispered.

He smiled slightly. "Then how can you remember this?" he stepped forward, taking her hand in his. She flinched, but he held on, squeezing it gently. "Very first word I ever said to you, trapped in that cellar. Surrounded by shop window dummies—oh, such a long time ago!" his eyes twinkled as he remembered. "I took your hand, I said one word. Just one word, I said—run!" He grinned again, waiting for her to see it.

"No," Rose whispered, and he felt both his hearts sink like lead. She dropped his hand. "No, you can't be him. I risked my life to save him—I—I—opened up the Tardis, and—I remember now! I became the Bad Wolf, and he kissed me! He—" she started sobbing, and he moved to put an arm around her, but she shoved it away. "He loved me!" she shouted at him. "The Doctor loved me, and he saved my life, and we were gonna be together—and now you're here and I don't know who you are, but I think you killed him!"

Each word felt like a stab in his newly-formed hearts, beating faster with the pulsing regeneration energy that surrounded them still. "Rose," he protested, feeling his own voice getting louder, "He did love you! I love you! I'm trying to do that, right now and you're making it ha—" he clamped his mouth shut, biting his lower lip. He'd been created for this girl; he had to keep trying. He could NOT mess this up, or it would be over—over as soon as it had begun.

"Rose," he coaxed, more gently this time, "Come with me. I can show you what the Doctor's like now. I can show you—where he is." he pointed toward his own chest, trying. Trying to show her.

Tears were still flowing freshly down her cheeks. "You're a liar," she sobbed, hurting him even more. "You're nothing but a liar and a mad—sick—messed up guy!" Rose ended, yelling.

His mouth twitched. "She doesn't mean that," he thought to himself. "If she really believed I wasn't the Doctor, she'd come with me to find out where he was. She'd be threatening me right about now, not crying and shouting."
All the same, though, she was next to the door. He watched her, his mouth in a round 'o'. It was hard to believe she was actually doing this. Didn't she know what wonderful things they could do together?

"Take me back," she shouted at him, tearfully. When he hesitated, she shouted at him again. "Take me back, right now! Take me back to my Mum! I don't want to do this anymore!"

Hastily, he found his now-shaking hands on the Tardis controls, resetting their course from Barcelona to Earth, 2005. He gulped in a breath, bravely still attempting to talk with her, to convince her otherwise. "Right then. Powell Estate, December 24, 2005, London, Earth, Sol System. There was something significant about that date—now what was it?" he scratched his head, trying to remember.

Suddenly he snapped his attention back to the present. "We're on our way," he reassured her, standing up and folding his arms over his chest with a frown. "Now are you sure you don't want to stay?"

"We'd better not land in Cardiff!" was all she managed to yell back, sniffling.

He instantly took offense at the barb, both toward his ship and his driving abilities. "We're not going to land in Cardiff!" he exclaimed, making a face. "We'll land in Jackie's living room, if that's what makes you happy! It sure takes a lot to make you happy, doesn't it?" His anger was building, and for some reason, his mind wasn't working right to control it. It was as if a part of his brain had suddenly shut down, and he started to feel a burning sensation at the back of his throat, as if some of the regeneration energy hadn't been expended properly. Not only that, he actually sounded pretty normal, like his old self that had died two minutes ago.

"All I want is MY Doctor back!" Rose shouted back.

"Oh, come on!" he snarled, slapping the Tardis console, for which she sent him a mental smack. "All I did was change! It's not like I just—GAHRGH!" he choked, his knees suddenly going weak under him.

Rose raised her eyebrows, a frightened look in her eyes.

Angrily, he tried again. "I said, I didn't—BARGH!" his hearts were beating faster, faster than they were ever supposed to. He put a steadying hand on the console as heat rose into his face, and he suddenly, weakly, exhaled a thin cloud of glowing, yellow energy.

"Who are you!" Rose shouted, a terrified look on her face.

"I just changed!" he shouted at her. "I just changed, a teeny, tiny bit, and now it's going all wr—GAGH!" he gagged, bending over at the waist as his body convulsed forcefully, trying to expel the rest of the regeneration energy.

Suddenly he shot up. "Christmas Eve!" he grinned, as if nothing had happened. "I knew we were landing on a good day!"

"Wait, where's Captain Jack?" Rose suddenly demanded, hand on the door handle. "Where is he? We should go back and get him! Why did you leave him there?"

"Captain Jack?" he panted, almost in a whining tone. "I nearly died, you're going home, and you're wondering about Captain Jack? Do you know how far away we are from him right—ARGFH!" he convulsed again, then gasped for breath as he grabbed for the Tardis console. He knew he should stay away from it—the energy was affecting his mind—but— "I think I'll use this one; yes!" he muttered to himself, flipping a new switch from under the dash.

The Tardis rumbled and jerked suddenly under them, causing them both to stumble over whatever was close by.

"Don't you dare touch anything!" Rose cried. "We'll never get home if you do something stupid!"

The Doctor laughed maniacally; he was seemingly unable to control his own actions. To him, Rose's concern suddenly seemed hilarious! "Just putting on a bit of speed! That's it!"

In fact, he nearly forgot that she was even in the room, and flipped another switch, pushing buttons and dials that he hadn't used in centuries (and there were plenty of good reasons why, which he'd forgotten all of a sudden). "My beeeautiful ship! Come on, faster—attagirl!" he growled in pain, gripping the side of the console where the coral grew up the sides. "Whatta you think? Faster? Wanna break the time limit?"

He was muttering just to the Tardis now, but his body was so bursting with energy that he couldn't even hear her inside his mind anymore. It was just a mad conversation with himself, as he wildly danced around the console, his extra-long arms and legs flopping around like a teenage boy's.

"Stop it!" Rose shouted at him, her voice growing angrier by the second. "Stop it! You're going to kill everyone! The Tardis, me, you; all three of us are gonna die when you crash this thing who-knows-where!"

"Oh, come on!" he growled back, "let's have a bit of fun for once! We're gonna rip through that Vortex! Hot Dawg!" he gasped in pain, then suddenly looked up at the Tardis columns with a look of apology in his eyes. "I'm sorry," he managed to say to her, not to Rose. "I'm sorry—regeneration's gone wrong again and I –ah, my head!"

He bent over again, then suddenly yanked his body upright again, the crazed look having returned. "FASTER! Let's open those engines! Yes! Woohoo!" An alarm bell started ringing in the distance as he continued to laugh maniacally.

Rose wished with all her might that she knew how to fly the Tardis, and berated herself for the second time that day for never having learned. Now she was stuck in the beautiful, old ship with a crazed madman in the Doctor's black leather coat, they were crashing and probably about to die, and she didn't have a clue as to how she could stop him!

She screamed as they hit another bump, knocking both of them to the floor.

Just then, everything went silent except for the Tardis.

The ship was heaving; great, groaning sounds as if she were breathing hard after a long run. But for now, they were apparently safe.

Rose picked herself up, gasping for breath, and reached for the door handle with a hand shaking so badly she could barely open it. She was so scared that she jumped up and ran outside as fast as she could, without even looking to see where they were landed.

Miraculously, they were actually back in the alley outside the Powell Estate. She breathed a huge sigh of relief and nearly collapsed into her mother, Jackie's, arms as the older woman came running up to meet her with Mickey alongside.

"Mum," she whispered in a weak voice, "Mum, you have no idea what this day's been like!"

"Oh, Rose!" Jackie cried, petting her hair softly and rubbing her back with her other hand, "I was so afraid you wouldn't come back! What's happened to you?"

Suddenly, the Doctor appeared at the door of the Tardis, gazing open-mouthed at the atmosphere of the planet, and propping himself against the doorframe with both hands.

Rose turned around and narrowed her eyes at him.

The Doctor's eyes wandered around for a few moments before he finally caught sight of her. "So you—" he stopped for a moment, swallowing as he tried to remember all that had taken place, "You are—not—coming with me, then? I kind of want to go to a nicer place—somewhere with more beaches, and maybe a bit of archery; some Zelths with needle-noses—" his gaze wavered for a moment as he rambled, then settled back on her. "No?"

Rose looked at him blankly for a second, than shook herself. "No," she answered firmly, laying a hand on her mum's shoulder.

He exhaled through his cheeks, making a bubble with his mouth and blowing it out. "Okay, then," he answered, sounding indifferent, "I'll be gone in a tic."

He stepped back inside and closed the door.

Silence sort of fell on the little group outside the time ship, as Rose collected her thoughts and Jackie and Mickey tried to think of something to say.

"Who's he, then?" they both asked at the same time, then looked at each other awkwardly.

Rose sighed, shakily. "He's what happened to me today," she tried to explain it, even to herself.

"So where's the Doctor?" Mickey asked, raising an eyebrow.

"He's—" Rose tried, "He's—"

She realized she really didn't know where the Doctor was. He'd said he was going to change, but she'd already established that the man in the Tardis couldn't possibly be the Doctor, or at least not HER Doctor, could he?

"He's not—" she tried again, "gone."

"What do you mean 'he's not gone'?" Jackie demanded anxiously.

Behind them, the Tardis groaned once in preparation for takeoff.

"He's in the—oh, my gosh, it's really him!" her eyes suddenly flew open in realization.

Wind blew leaves and trash around them and started to whip at her and Jackie's hair as the Tardis continued to dematerialize, suddenly fading from sight.

Rose gasped, seeing it. "Oh, no, no no! I changed my mind! I didn't know!"

She ran toward the ship, throwing off her mother's desperate grip and ignoring Mickey's protests, covering the few yards as fast as she could go.

"WAIT! Waaaaiitt!" she screamed desperately at the fading ship, hitting the side without any effect. She stumbled onto the pavement face-first as it disappeared, leaving no trace, and the last of the piercing echoes of its departure left her ears.

Gasping, she felt the dirty ground beneath her, tearing her sweatpants and barely saving her face from a big, nasty scrape. She regretted it all now. How could she have been so stupid? The Doctor—that Doctor—was hers and she had let him run off with a new body and a mental state that could end up causing his own death, for the second time in one day. Hot tears started rolling out her eyes, down her nose, and onto the pavement and it took both her mother and Mickey to pull her back up off the ground.

Jackie pulled her into her arms, and she could sense her indignation at the situation, but Rose felt no more anger.

Only pain.

"I'm sorry," she whispered, wishing he could hear her. "I'm so, so sorry, Doctor, I'm so sorry!"