The Prisoner

A Doctor Who/Harry Potter crossover.

Disclaimer: All recognized entities are property of the BBC, Warner Brothers, or J.K. Rowling. I am not making money off of this piece of fiction.

AN: This is both my first Doctor Who and crossover fic. I have been a DW fan for about two weeks. While I have pulled some information from the couple of dozen of episodes I watched (I'm OCD), I filled in the gaps using Wikipedia. If I made a glaring mistake, please tell me.

This is a fourth Doctor fic. While David Tennant is awesome, Tom Baker in my novice opinion is the Doctor. (Plus the scarf is awesome. I needed to include the scarf.)

Added note: Someone pointed out that I got the Merlin part wrong. Changed it to another name.

Regulus sighed as he placed another sheet of parchment into the outbox. He thought that life as a Death Eater would be glamorous, that he would be fighting the mudbloods and blood traitors for the true place of the purebloods. What a fool he was, thinking that he would suddenly rise up in the ranks all because his familiar connections.

Restless, he put his hand in his pocket, fiddling with the seams inside. It was a bad habit of his, always doing that whenever he was bored or restless. He ruined many pockets because of this fiddling.

As he grabbed the next piece of parchment, he noticed another prisoner on the roster who had been imprisoned. The prisoner, whose name was listed only as "The Doctor", had been confined to the dungeons for nearly a month.

Regulus found that odd. Only purebloods or important people were detained, and never that long. All the others were put to death.

He didn't know who this "Doctor" fellow was, nor did he recognize it to be the name of any prominent pureblood family. It was a rather odd name, too. He thought that doctors were Muggle healers, and he saw no reason why the Dark Lord would want to detain such a person for so long. Why was a Muggle so important to him?

I must be crazy, thought Regulus. He shrugged, filing the name away for later.

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The next day, he went down to the storage area containing the prisoners' personal items. Technically he wasn't supposed to be there, but he assumed he would just tell them he was just inspecting the items to complete his paperwork.

Personal items were kept only in case they were important to the cause. He wasn't expecting anything to be available on this Doctor person.

Instead, he found a rather large, hefty drawer devoted to the prisoner. Inside, he found things that he would consider to be innocuous. He first pulled out a long, multicolored scarf. Regulus thought it odd to keep a scarf, though he really didn't know the exact protocol for deciding which item to keep. Next he found a bag of jellybeans. Again, odd, but he assumed they must have held some purpose. He then pulled out something he assumed to be a key. It could have been more important, considering the ankh-like shapes printed on it.

He paused as he took out the final item. It was some sort of long, metal device. He examined it closely, trying to figure out its purpose. As he inspected it, his finger came across a button. Thinking nothing of it, he squeezed it.

Suddenly, there was a loud clatter. The contents on the table slid to the floor as the leg detached itself from the top.

As he cleaned up the mess, he realized why this prisoner might be special.

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With the device safely tucked in his pocket, he walked resolutely down to the dungeons. He got permission to visit a prisoner, claiming he was under orders to do so.

Coming up to the cell, he fiddled with the lock and opened the door.

Inside, he found a man sitting against the far wall. From what he could see in the dim light, the man had a mop of curly, messy hair that seemingly hadn't been washed in awhile. His clothes, from what he could tell, were a short jacket of some dark color, and some sort of light-colored trousers. The rest of him was shadowed in the dark of the cell.

The man looked up from his crouched position. Jumping up, the man jubilantly says, "Hello! Sorry I'm not my best at the moment. Would you mind getting us some tea? I'd love some. It's always good to talk over a good cup of tea."

The man must be insane, thought Regulus. Courteously, he says quietly, "You must be the Doctor."

The man grinned wildly. "Yes. Yes I am. And who might you be?"

Regulus merely shook his head. "Never mind that. Who are you?"

"I'm the Doctor."

"Doctor who?"

The man chuckled slightly. "Just the Doctor."

Regulus sighed dramatically. "Why are you here?"

"Just passing through. I thought I'd take a long holiday, but trouble always seems to catch up to me."

Regulus thought they were going nowhere. "Well, thank you for your input, Doctor. I hope to talk to you again soon."

The man nodded. "My pleasure. The best interrogation I've ever had, really."

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Regulus sat over his paperwork, pondering the man. Ordinary looking, really, he thought. Seemingly harmless, but that can be deceiving. Probably trying to get on his good side so he'd help him out.

Frustrated by the eccentric prisoner, he put his hand in his pocket out of habit. His hand fell onto something cold and metallic.

Regulus nearly slapped his face in realization. He didn't ask the man about the device!

Realizing he couldn't go and ask the prisoner about at the moment, he filed the information away for later.

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A couple of weeks later, he got approval to go visit the cell again.

As he entered the cell, the Doctor jumped up again, saying amiably, "Hello again. I never thought I'd see you again. Everyone seems so busy around here, I never have time for a good chat."

Annoyed, Regulus went right to the point. Pulling out the device, he sternly demanded, "What is this?"

The man stepped slowly towards him. "Ah, I thought it was lost. Where did you find it?"

Regulus demanded more strongly, "What is it?"

The Doctor chuckled. He suddenly extended his hand toward Regulus, nearly pouncing. Before he could grab the device, Regulus stepped out of the way, back up slowly. "What. Is. It?"

The Doctor snapped his fingers and, rocking gently on the heels of his feet, replied, "Why, it's a sonic screwdriver."

Regulus paused, waiting for more. When he realized the man wasn't going to elaborate, he asks, "What's a sonic screwdriver?"

"Oh, great device really. It can unlock or repair any device. Now, if you don't mind, it's very valuable to—"

"If it's so valuable, why would the Dark Lord not just take it for himself?"

The Doctor started restlessly pacing across the room. "I would imagine he doesn't know what it is. I don't know how he even knew who I was. As soon as I was pulled into his chambers, he muttered my name and ordered me to the dungeons."

Regulus found that odd. "Why would he know your name?"

Still pacing, he replied, "I imagine I will come across an earlier version of him sometime later. That does tend to happen to me from time to time."

The man really was insane. "What?"

The Doctor smiled at him and said, "Oh, did I not tell you? I'm a Time Lord."

"A…what?"

"A Time Lord. I can travel across time and space, getting myself into all sorts of adventures."

Regulus was dumbfounded. "I don't believe it."

"I'm quite serious. I travel using my TARDIS."

"TARDIS?"

"Yes. Time And Relative Dimension In Space. I left it in a field somewhere around Birmingham. You can look for it, if you want. Actually, I'm rather worried about it, if you don't mind checking up on it. You'll need the key, though. It's in the shape of a police box. The TARDIS, that is"

Regulus, still looking dumbfounded, asks, "Police box?"

The Doctor stopped his pacing, turning to Regulus, "Yes, a police box. Unfortunately, its chameleon circuit broke down awhile back and I haven't gotten around to fixing it. I'm rather fond of the shape, actually, even though it does stick out a bit. There aren't too many police boxes around, you know, especially in other galaxies."

Regulus stood there gaping at the man. Shaking himself out of his stupor, he backed out of the room slowly, saying, "Right. I'll check up on this TARDIS of yours."

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Regulus checked every area near Birmingham, looking around for the elusive TARDIS.

Gripping the key in his hand, he fumes at himself for believing an insane man's babbling. Silly. Just silly. Why do I believe a man who must be insane? And why am I looking around for a bloody police box in the middle of some damned Muggle area?

Walking around in a field, he spots a blue box-shaped object a few meters away. Running up to it, he saw the distinctive shape of what appeared to be a police box.

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Regulus flung open the door to the Doctor's cell.

"Did you find my TARDIS?"

Numbly, Regulus nodded slightly.

Coming closer, he asked cautiously, "Who's this Dark Lord anyway? Why would he want a Time Lord?"

Thinking it was a rhetorical question, Regulus asked, "Why?"

"I don't know. I'm asking you." The Doctor then dropped his voice down to a whisper. "I think I know why. Time Lords are seemingly immortal, though I do have to say we are quite not. If the Dark Lord wanted to have the power to possibly live thousands of years, he may have kidnapped me to weed out the secret."

Regulus' face paled. The Doctor stared at the young man and said in a normal voice, "Are you all right?"

Looking straight at the Doctor, he muttered, "We have to get you out of here."

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Regulus snuck back to the cell at nightfall. Under his cloak, he held the Doctor's personal belongings wrapped within a dark, long cloak.

He opened the door to the Doctor's cell and quietly slid inside.

The Doctor was sitting in his usual position, seemingly asleep. He walked up to him, shaking him awake.

He blearily looked up at the young man. "What's the matter?"

Regulus shoved the robes and belongings into his lap. "Wear this. I'm breaking you out."

The Doctor stood slowly and shrugged on the robe. Quickly and silently, the two sneak out.

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Regulus apparated them to the park across the street from Grimmauld Place and quietly snuck inside.

"Master!"

The Doctor jumped. "What's that?"

"That," Regulus walked up to Kreacher. "Is my house elf."

"House elf?"

Regulus chuckled. "Yes. My house elf. He's loyal to me. He's a rather big help in the house."

The Doctor could only nod.

"Well, this is my home. You're safe here. My father was arrested awhile back, so I am now the head of the house. My mother is in her bedroom, but she has gone mad. Just stay away from her bedroom and you shall be fine. Come," Regulus beckoned to him. "Join me in the kitchen. I believe I can offer you a spot of tea now."

"Why did you help me escape, anyway?"

Regulus opened his mouth to speak, but quickly shut it. Muttering, he said, "It's nothing. Nothing, really."

Clearing his throat, Regulus continued. "What do you know about the wizarding world?"

"Well, I had not encountered anything of your people until now. I assume that the wizarding population descends from a Carrionite/human union. If so, I have met a group similar to your people. The union was probably formed to create a new, powerful race of aliens, but the plan must have backfired when the birth of their offspring was botched."

Regulus chimed in, "But the first wizard was Mago. Are you saying that he was descended from these—"

"Carrionites. It's just an assumption, of course. The offspring of the union was probably unwilling to go along with the destruction of the world and instead used it to create good on Earth."

"What are these Carrionites, anyway?"

"They are a witch-like race from the Fourteen Stars of the Rexel Planetary Configuration. While they appear to use magic, it is actually a highly advanced form of science that uses words instead of maths."

The Doctor cleared his throat and continued, "Now. Tell me about this Dark Lord…"

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All squeaky clean, the Doctor was wandering around the house, looking at the scenery. He knew he had to leave soon, but something told him that something big was going to happen and that he'd be a part of it. Just then, while passing the drawing room, he heard voices talking insistently. Putting his ear to the door, he listened intently.

"Kreacher, remember that cave the Dark Lord sent you to?"

Oh yes, Master. Kreacher remembers it well."

"Will you take me to it?"

"Please, no Master! It is not a good place!"

"Kreacher…I am your master and I command you to go there."

"All…all right, Master. We shall set off."

The Doctor then decided he needed to find out about the cave that was apparently important to this Lord. He knocked the door and called, "Black, I want to ask you something about some of the objects. It may come in handy—"

Regulus swung open the door, staring wildly at the Doctor. "You need to go away. Something important is about to take place and I cannot have you interfering."

The Doctor shoved himself into the doorway. "I'm afraid I overheard some of your conversation. Where is this cave and why is it so important?"

Regulus stood there, wild-eyed and fuming. "This is none of your business. Now please leave where you came!"

The Doctor stood defiant in front of Regulus, and stated calmly, "I will not leave until you tell me more about this cave."

Regulus backed down, sighing. "Fine, as long as you leave afterwards."

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Regulus apparated the Doctor to the field. He watched as the Doctor walked back to the TARDIS.

The Doctor turned suddenly to Regulus and said, "I thank you for freeing me and providing such hospitality. I hope we meet again someday."

Regulus stared at the Doctor, composing himself. "Yes. Well. I'm happy to oblige. Now, please go."

"Right." The Doctor walked over to the TARDIS and opened the door. With one last glance behind his shoulder, he walked in.

The Doctor, inside the TARDIS's control room, quickly engaged the TARDIS. Muttering slightly to himself, he set the controls swiftly, intently monitoring the coordinates.

The TARDIS started back up, its sound reverberating within the room. Within a couple of seconds, the TARDIS touched down, reaching its destination.

The Doctor quickly opened the door and poked his head out. Outside, he could see the faint outline of Regulus and Kreacher approaching a bowl. The underground lake faintly glittered in the light of Regulus' wand. He watched as Kreacher quietly told Regulus something. He, almost defiantly, took the bowl and downed the liquid inside.

The Doctor was appalled at the results. Regulus twisted wildly, as if delusional from the drink. He forced more of the liquid down, obviously affected by whatever it was.

As he placed the bowl down, the Doctor noticed something stirring within the water. Disgusting, twisted humanoid-like creatures rose from the water, hobbling slowly to both Kreacher and Regulus. Still disoriented and slightly crazed from the liquid, Regulus loudly ordered Kreacher to leave. Pausing slightly, the house elf disapparated, leaving his Master behind to the mercy of the foul, zombie-like creatures.

Realizing that Regulus was just going to let himself be overtaken by these monsters, the Doctor ran over to the man, kneeling down to where he had fallen. Regulus fought off the Doctor, but was quickly overtaken when he scooped him up into his arms.

The monsters grabbed at the Doctor's legs, but they could not get a grip on the running man. He quickly entered the TARDIS, placing the now-unconscious Regulus on the floor. The Doctor ran to the controls, flying the TARDIS off to somewhere other than the evil cave.

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Regulus woke sometime later to the Doctor kneeling over him.

He tried to sit up quickly, but the dizziness soon overtook him and he sank back down to the floor.

"How are you?" the Doctor asked.

Regulus blearily stared at the man and asked in a raspy voice, "Where are we?"

The Doctor smiled slyly and responded, "The moon."

Regulus rolled over onto his side away from the Doctor. "I must be dead."

"No." The Doctor edged to the other side of Regulus. "I brought us here. There's nothing here that can harm us for the moment. I thought you needed some time to recuperate."

Blinking, Regulus said, "I would have been fine without your help, you know."

The Doctor laughed heartily. "No, you would have been dead. That is hardly fine."

"It was for me. I stopped that heartless bastard from killing off more innocent creatures. My Kreacher…"

"Your house elf is fine. He disappeared as you had ordered, and is now probably taking care of your mother as we speak."

"But…" Regulus had an odd look come over his face. "He thinks I'm dead." Burying his face into the floor, he muttered inaudibly, "I should be dead."

The Doctor scooted closer to the prone man and said, "Now, now. You're more helpful alive than dead. This way, you can do more to stop him."

Regulus let out a heartless, barking laugh. "No I'm not. If I go back down there, he'll know I'm alive. He can sense me through this." He slowly sat up and pulled up him left arm sleeve.

The Doctor stared at the hideous mark on the man's arm. It seemed quiet, faint, though he realized it might be something more than just an old tattoo. "He's marked you?"

"For life. This allows him to sense, call, and possibly torture us. He knows where I am using this mark."

"Well." The Doctor paused in thought. "It would seem that he does not know you're here or else it would be more active. I assume that he cannot sense you if you are outside his space or time."

The young man stood, asking, "What should I do then?"

"We," the Doctor said as he stood. "We will find a way to get rid of that mark. Until then, we can find ways rid him without being near him."

Regulus walked up to the eccentric Doctor. "How would you propose that?"

"Well, I suggest we take a bit of a break first. There are many other places to see, and you will probably need a rest first."

He paused in thought. "Where would you suggest we go? You said you could travel through time and space."

The Doctor stepped joyfully to the controls. "Anywhere! Are you with me?"

Regulus grinned and walked up to the Doctor. "Yes. Yes I am."