**Author's Note: SO...this is my first Doctor Who fanfiction and I would really like to hear what people think of it. I have some ideas for additional chapters but will need some inspiration. I worked VERY hard on this and would really appreciate it if people would tell me if they see any errors or things that they feel could be written differently in order to make it more Doctor Who-ish. Thanks in advance!!! :)**

The door swung inward. The Doctor stepped out onto the dark metal floor and paused, confused, as he took in his surroundings. Instead of 21st century London he found himself in large metal clad room that was filled with architecture and technology that was distinctly not human. He turned to his blue box.

"What have you gotten me into this time?" He chastised playfully as he closed and locked the door. "I can't wait to find out!" He turned on his heel and started off with a bound.

He stopped at the door of the room and peered around the corner into the vast hall. Once he had determined it was empty, he turned the corner and made his way down the expansion of doorways. He stopped at a console with a large touch screen and, after a few tries at a manual override, he pulled out his sonic screw driver and aimed it squarely at the screen.

"Well, that can't be right. I'm not even in the same millennia. I wonder why I'm here…"

"Halt! Name yourself." When he turned he found himself facing a knight. The man before him wore a technologically advanced armor that resembled a traditional Earth knight, which The Doctor found endlessly amusing.

"I am The Doctor."

*****

"Now, when I said I was The Doctor I didn't mean THE doctor…well I did, just not…Oh, Hello!" He said as he stumbled down the short stair and the door shut behind him. Two identical blonde women stood up from a circle of three chairs in the center of the room while a third, a brunette and far more angular than the first, remained seated and uninterested.

"Oh my, Darla, what has Daddy sent us this time?" One of the blonde girls asked as she slowly approached The Doctor in a manor that was more predatory than curious.

"I think it's as good a time as any for us to find out, Carla." Replied the second blonde, whom he assumed was Darla.

"Darla, Carla, please ladies. There's been a misunderstanding. I'm not the doctor. Well, I am The Doctor. It's a bit complicated. You see…" The two girls circled him.

"Enough." The voice was firm and unforgiving. "You both need to stop. I've had enough. How long do you think before we run out of doctors?"

"You're really no fun at all, Isadora." The two girls pouted and went to a couch on the far end of the room. They sat on top of one another and began to play with each other's hair.

"Isadora? Wait! It's an important name. I know that name. Carla, Darla, twins, knights, Isadora. ISAdora." He paced the floor a bit. The third woman finally stood from her chair and began towards him. He stopped pacing and stared at her, mouth open slightly as though there were words in his mouth waiting to explode out into the open air.

"I should hope you know my name. I am your princess." She was fairly tall. Her face was strong and her golden tan skin nearly sparkled in the light of the room.

"Of course you are. Princess Isadora Evanthe of the Briseis on the planet of Trifena in the Galatea Galaxy. I'm so thick. How could I have missed that?" He spun in place from his excitement. "Please, forgive me, Princess," he bowed, "I've not been myself today."

"Oh! Did you hear what he said, sisters?!" Carla squealed in terror.

"I heard! Did you hear, Isa?!"

"Calm yourselves! I'm sure that he didn't mean it like that." Her eyes narrowed at him. The identical girls clung to each other.

"Mean it like what?" The Doctor looked back and forth between the three girls.

"Surely you've heard, Doctor." It was Isadora who spoke.

"I'm afraid I'm not from around here." His face was full of concern. "What is it? What's been happening?"

"Come, Doctor, I will show you your quarters." She threaded her hand through to the inside of his elbow. Once they were in the hallway and the door had closed behind them she began to speak again. "I chose not to talk about this in front of my sisters. They have a tendency to act like children and are therefore particularly affected by the things that have been happening. There have been many people around here who have not been themselves. Soon after they begin acting odd they go trying to kill people. When we capture and lock them up they lose all memory of their actions. No one has been able to decipher what has been happening. It is your job to take care of us and solely us."

She pressed her hand onto a module by a door and motioned for The Doctor to do the same. The door opened into a large room with rose marble floors and gold leafed columns. The furniture was plush and extravagant, clad in red and gold silks and velvets. She waited at the door as he stepped into the room.

"What's this, then?" he said as he spun slowly in the center of the room.

"I told you, your quarters. On the far wall is the console that controls the various atmospheric qualities of the room. You have approximately 5 minutes to take a quick look around the room and then you must return to our sitting room. Be sure to lock your door by pressing your hand to the console as you leave. Other than me, you are the only person who can open this door."

"Thank-you. Thank-you very much, Princess Isadora Evanthe of the Briseis." He said with unusual enthusiasm and enunciation of every syllable. A crazed grin stretched across his face as he watched her exit the room. "Princess Isadora. She's more than I expected. Anyway," He said with a start and hurried across the room to the console she had spoken of, "What's going on here that has the people going all odd and blood thirsty." He took his sonic screwdriver back out and pointed it at the screen. After a thorough scan of the system he began pacing the room. "Nothing off in there. So what's going on here?" Just as he finished his sentence a blood curdling scream echoed through the hall out side his room.

*****

A woman crouched over the motionless body of another woman. You could hear the crouching woman weeping over the body. The Doctor quickly went over and crouched next to the body, pulling a stethoscope from his pocket. He checked all of the places he could think of her heart being and frowned when he found no signs of life.

"Who are you?" The weeping woman asked.

"He's the doctor." Came the chorus of two familiar voices that he'd rather not ever hear again. They glanced around the room in unison and wore identical confused expressions. "Where is our sister?"

"I though she was with you." He responded, his face screwed up in confusion.

"You let her go off on her own?" One of the girls shrieked.

"Guards!!" The other yelled into the hallway where they had been gathering, waiting for instructions. "This is of no importance. You must find the Princess Isabella." The two turned back into the room to face an irritated Doctor.

"'No importance?' There is a woman dead. Surely that is of some importance." He chastised as he pushed pass them.

"It will do you well to learn that our sister's safety is more important than the deaths of a thousand slaves." His anger grew with the girl's every word.

"That is not even remotely true, Carla. It would do well for you both to understand that no one person is worth more than another. Especially you, Carla, being the oldest of us and the next in line for the throne." Isabella stood to her full height as she navigated through the crowd with the grace and poise that her sisters clearly did not poses. "What has happened here?"

"One of your dressing maids, Tarra, has become a victim of this mysterious homicidal infection." Darla snapped, obviously irritated with the tone her younger sister had taken.

"Who did it?" She rushed into the room.

"What did it? What?And that's what I'm going to find out." The Doctor ran back through to the room's console pulling out his screw driver as he went. When he got to the console he adjusted the settings and pointed it at the screen. After a few moments of confused looks he banged the screw driver a few times with his other hand and pointed it back at the screen. "Why isn't this working?"

"What are you trying to do?" He was startled by Isadora's closeness and tried to smile to cover it.

"I'm trying to access the security mainframe to see the video taken by the security cameras in this room." He began to examine the console with the same confused look.

"Here's your problem," Isabella said as she pointed to the label on the console, "it's an Atmospheric Console. It is in no way connected to the security system because you never know what people can do, do you Doctor." The whole statement dripped with meaning. "I think that we should leave this investigation to the experts."

"Oh, but I am the experts." He grabbed the Princess's hand, at the gasping surprise of a few of the people in the room. "Come on, then! Where's the nearest Security Console?" He said running out of the room trailing Isabella behind him.

"Twelfth floor security room." Her breathing was labored as he pulled her around the hallways. "Doctor?" He kept pulling her along. "Doctor?!"

"Yes?" He stopped suddenly and she fell, full body, into him. She looked deeply into his eyes and her face went blank for a moment. "Yes, Princess Isabella?"

"Call me Isa." She smiled weakly still looking into his eyes.

"Okay then, Isa." He said with special attention to her name and turned from her to begin pulling her along again.

"And," she said suddenly and loudly. He stopped and looked at her expectantly. "we are on the 13th floor. The lift is back there."

"Oh! Okay, come along then." He said, retaking her hand to pull her along behind him.

*****

The Princess placed her hand on the lock and the door labeled "security" swung open to reveal several viewing screens and a much larger console. Wordlessly, The Doctor sped into the room and began to work on the console. Isa watched him, studied him, while he concentrated on the various screens that flashed before him.

"Who are you, Doctor?" He looked back at her. She stood tall with her arms crossed. Despite her aggressive posture, her face was merely inquisitory.

"Not important." He said distractedly, turning back to the console.

"But it is, Doctor." She slowly stepped up beside him and began to play with her fingers.

"No, it's not." He said with the same tone.

"You are in my castle chasing a murderer and…" She paused trying to find her words. He stopped what he was doing and turned to her again.

"And what?" his voice was cautious.

"There's something strange in your eyes." She glanced back and forth, carefully avoiding his stare.

"What do you see?" It was his turn to be curious. Her eyes stopped darting around and locked onto his.

"Forever. The vastness of eternity. Loss and pain. Love and friendship. Hate and fear. Everything. It's like you've got everything there ever was and will be locked up in that head of yours." He continued to stare at her, trying to sum her up. They stood that way until the console made a few bleeping noises and he turned to it.

"AH! There we are. Video feed for room I95-13. We'll just rewind it a little bit…and play." They both watched the screen as a large burly looking man walked over to the woman and picked her up off of the floor. A blackness surrounded the two and filled the room blocking the view of the camera. When it dissipated the large man dropped the woman to the floor.

"Wait, that's not how we found her."

"Keep watching." The Doctor said as he peered at the screen. The man knelt down, expressionless, beside the woman and straitened her out, pulling her skirt down properly and folding her hands over her chest. "Interesting. The host seems to maintain some sort of control. At least as far as this creature allows them to."

"What creature?" She demanded.

"I don't know. Why don't I know? What am I missing? OH my head! My head! My thick stupid head. There's too much stuff inside my head. Black misty…stuff. Muderous tendancies. Jumping hosts. Think-a-think-a-think-a-THINK!" He paced back and forth and back and forth inside the small room making exaggerated gestures and occasionally hitting the side of his head. "Right! Has there been any off world cargo ships?"

"Yes. I believe there was one."

"Where was it from?" She shook her head gently as a pensive expression crossed her face. "Come on, think!" he said taking her by the shoulders and shaking her slightly.

"Uh…" she looked around, searching for the memory in her mind. Her face lit up. "It was a trader of precious jewels from Zosimos."

"Zosimos. Zosimos. THAT'S RIGHT!" She jumped at his exclamation. "Zosimos is destroyed by a parasitic mist called The Kalaporian Mist a month from now. One of their crew must have brought it here and it passed person to person until it reached the royal castle, but the question is: Why? To find out why we have to find the host. Come on, then!" He grabbed the Princess by the hand and dragged her out of the room with his screw driver before them.

"How are we going to kill it?" She asked as he again pulled her through the halls.

"If we don't have to, we won't. We have to give it a chance to leave. The Kalaporian Mist doesn't have to live inside another being, it chooses to for its own personal gain. We are going to give it the choice of leaving." They turned a corner sharply and she nearly lost her footing.

"And if it doesn't?" He ignored her question. She yanked him to a halt, digging her heals into the floor. "You listen here, Doctor! I'm already allowing you to drag me through my own castle in a very improper manner. If I'm to let you drag me to face death, you need to tell me what you plan to do."

"I can't"

"Why not?!" Her voice was indignant.

"Look, Isa, you have to trust me. I can't tell you. If you were to become infected the Mist would know everything you know. If he knows my plan it will never work." She stared at him hard, studying his face and eyes, before she finally nodded and held her hand out to The Doctor.

"Let's do it."

*****

The Doctor stopped suddenly.

"Something wrong, Doctor?"

"This is taking too long. There has to be a better way. There's no way to track it and the castle is just too big for my screwdriver's sensors." He paced back and forth again. She watched him, still trying to figure him out.

"I've got it!" She exclaimed suddenly.

"Got what?" he said, stopping.

"I know how to find it." She ran a little further down the hall to the nearest console and began to press the screen. He watched the screen closely. "The consoles in the halls are meant for informational purposes. They can tell you how many people are in the castle at any point in time and where exactly each entity is."

"So it can tell us where there are two entities in the exact same spot! Brilliant! Now there's the Isadora Evanthe I know and love!" She was sure if he smiled any wider he'd break his face. The console began to beep loudly and a small circle on the screen was highlighted. "U01-25! That's the King's room! DADDY!"

This time she ran first and stopped suddenly at the lift. The Doctor used his sonic screwdriver to speed up the decent of the car. When the door opened she stepped in with The Doctor on her heals. She pressed the appropriate buttons and placed her hand on the elevator console. The elevator began its ascent, which was also assisted by the Doctor. The doors opened on the twenty-fifth floor and she dashed out into the hall and began to run the full length of it. The Doctor followed closely behind. She stopped at the very last door and placed her palm on the lock. Nothing happened.

- Hide quoted text -

"It's changed the lock! How could it change the lock?!" The Doctor gave her a meaningful look before pulling out his screwdriver, once again. He knocked the console off the wall with his foot. "No! Daddy!" The door opened and before he could stop her she ran into her father's room.

"No! ISA!" he ran in after her but he was too late. King Nikostratos Evanthe of Brisei had his youngest daughter by the shoulders. Between them was a black mist that was running out of the King's eyes, ears, nose and mouth and into the Princess. The king dropped the princess onto the floor and slumped over. Isa writhed on the floor in obvious pain for a several long moments before rising off the floor and turning to The Doctor. "Isa?"

"You know this is not Isa, Doctor. Unfortunately, because of this, I have to kill you." Her normally light aqua eyes were dark a soot as they laughed at him.

"What do you want from her?" The Doctor stood tall, every moment that passed fueled the anger he now so often felt.

"I've just learned from our beloved King that she is the next heir to the throne. No surprise there, what with the disappointment her sisters turned out to be." She slowly advanced.

"Ah, so with her you get your own kingdom." He looked at her with a frown. "I'm giving you only one chance. Leave and never come back."

"And why would I do that when I could have a whole planet to myself?" She laughed.

"Because if you don't I will stop you. Don't you know who I am?" He stepped closer to her. "I'm The Doctor."

"Even so, Doctor, I think I'll be staying. All the power…and she's quite beautiful, wouldn't you agree?" She traced the line of her waist with her hand.

"Why don't you take me instead?"

"And why would I…" She lurched forward.

"Doctor, kill me. She won't leave me unless she has to. Please, I…" She choked. "No! Not yet." She said to the entity inside her. "Now, Doctor! You won't be able to stop it if it takes over again." The Doctor went to her and brushed her hair away from her face. "You know I'm right."

"Isa…" He said sadly and brushed her hair off her shoulders.

He looked into her eyes as he placed his hands around her neck and began to squeeze tightly. She struggled for breath for only moments before she gave in. As the last strangled breath left her body, so did the black mist. He felt it seep into his body and accepted it with a deep breath. For a few moments he twitched and twisted about. When he finally stopped he exhaled deeply. With his exhaled breath came a white dust that floated to the ground in front of him. As soon as this process was finished he flew to the floor next to Isadora and pulled out his stethoscope. Finding just what he expected, he tossed the object to the ground and started compressions on her chest.

"Come on, Isa! Come ON! Don't do this to me!" He leaned forward and breathed deeply into her lungs. He began compressions again. "Come on, Isa. You have to live. You are going to be the queen. You will be known for the rest of history. Breathe Isa! Breathe!" He leaned forward again but before his lips touched hers she began to cough. He rolled her to her side and laughed heartily. "Ahhh, I knew you could do it. You are dazzling."

"What happened?" Her voice was horse. "I…did you…but I'm…"

"I am immune. That's the thing about my kind; we have extraordinary immune systems."

*****

"For extraordinary services to this kingdom, to me, and to my youngest princess, I dub you, Sir Doctor of…well where exactly are you from Doctor?" The king smiled down on him, his sword resting on the Doctor's shoulder.

"Everywhere, your highness. I'm from a little bit of everywhere."

"Fine then." He shifted on his feet and cleared his throat. "Sir Doctor of Everywhere!" The crowd cheered around them. "You may rise."

"Thank-you so much for that. Thank-you!" He shook the king's hand boldly and moved onto the identical princesses, started to talk and then thought better of it and moved on to the youngest princess. "Princess Isadora Evanthe of the Briseis on the planet of Trifena in the Galatea Galaxy, I'm going to miss you." She smiled at him.

He hugged her tightly, much to the surprise of onlookers and took a deep breath as he backed away. She watched his every step as he left the room and then looked over at her father. He smiled lovingly at his favorite daughter and nodded his head in the direction of The Doctor. She teared up and ran to him for a hug that lifted her off the floor. As soon as her feet touched the floor, they carried her to the blue box just as The Doctor was stepping in.

"Isa." She said firmly. He stuck his head back out and looked at her.

"What?"

"I told you to call me Isa." She stalked up to him.

"I'm sorry Isa, it just seemed appropriate." He smiled down at her.

"Take me with you." It wasn't a question.

"I can't do that, Isa. You see there are some things in time and space that can not be changed. They must stay the same or the entire universe is at stake. You must become queen. You will be known for all of eternity as the most beautiful Queen that EVER ruled, not just on this planet but all of them. You unify this planet single handedly and set up a trade program the likes of which have never been known. You must stay here and become that."

"I'm not going to be the Queen right this second." She paused to study his disapproving look. "How am I supposed to do all of those things if I've never seen anything? If I stay here I will know no more than this castle's walls. Does that sound like the kind of education that a great queen has? Please, Doctor, teach me the things that you know."

"You are clever." He smiled at her. "Lucky for you I have a time machine. I can bring you back to the instant after you leave. When we're through with our adventures, of course." He jogged into the box and she stared after him, shocked that she had won. "Well? Are you coming or are you going to stand there and watch me leave?" She stepped in and looked around the TARDIS.

"It's…" She began.

"…bigger on the inside."

"Well, I was just going to say huge but that as well." She went up to the platform to watch him work. "Anything I can do?"

"Pull that lever."