Exuro: Latin for burn.

That was what Donna was doing, from the inside out.

He had warned her, but even he hadn't taken the possibility seriously. Vampire, ha, there couldn't be such a thing. Just a silly myth. If he had believed it, even for a second, they never would have landed on the planet of Exuro, not for a holiday or any other reason.

Donna, who was now writhing on the bed in what had to be agony, had been begging for a couple days off from all the running and almost dying. He suspected she would take the running and plot foiling over this.

He had finally given in, thinking of all the beautiful sights he could show during the day. The planet had a series of waterfalls that were colored just so, that they looked were burning. He had figured they could have plenty of fun during the day, and stay in and watch bad movies during the night.

It had all started out well, they had walked to the waterfalls, he had managed to get her admit that he was a little impressive. All in all it had been a good day, built on the best of intentions. Making Donna happy, what could go wrong?

Then they had a stupid fight, all because he made a careless comment about how intelligent the indigenous race was. He hadn't meant anything towards her, he thought she knew by now that he thought she was brilliant, but he had clearly been rude.

He had gone to his adjoining room, and well, frankly, he pouted. He had been hoping for some cuddling, and maybe even getting some actual rest if she didn't make him to sleep in his own room. Him and his big mouth.

After he had decided maybe he had given her enough time to realize that he hadn't meant to hurt her, he had gone back to her room to find it empty.

He hadn't thought she would go outside, he had told her not to after all, but he hadn't been able to find her inside anywhere. So, the Doctor had set off in the direction of the TARDIS thinking that maybe she had headed that way. The longer he went without finding her, the more worried he got.

He became frantic, scared that maybe the myths were true, and it would be all his fault if something happened to her. How could he live with himself, Donna was his best mate, his very best mate?

He began to scream her name, hoping that if there was anything out there he would call their attention to him instead.

He found her in a bush, not too far from the TARDIS. There was blood, shining in the light of the three moons, rolling in two neat rivers on her neck. He heard movement, and rushed to Donna's side, putting his body in front of hers. It seemed as though the noise was moving away, and he imagined that he must have scared the creature away.

With a trembling hand he reached out, touching the opposite of her neck, on her pulse point. She was alive, he breathed out a sigh of relief. Her heart was beating at a speed it couldn't maintain, but for now she was alive.

He pulled her up into his arms, and any hope of relaxing was long gone. She was alive, she was alive, and it became his mantra with every step to the TARDIS. He had gotten there quickly, and the doors opened to him as they always did when the situation was dire.

The med-bay was the first door he had come to and he had laid her out of the bed, but he was losing hope rapidly. Her pulse had increased, and she had begun to shake.

The Doctor ran every scan that the TARDIS could perform, but it was too late. He was informed there was nothing on board that could stop the venom that was coursing through her veins.

Now he sat here, her back on her bed, him on the end. He was tense, possibly because if she woke she might decide he was a snack, but mostly because he feared for her.

How long would she hurt? What would happen if she woke? He wasn't just going to leave her here, and he wasn't just going to give up on her, not when he lov…not when she was his best friend.

Something hard smacked into the back of his head, and he groaned and rubbed at it, before searching for the projectile. It was a hypo spray, and clearly the TARDIS wasn't happy with him at the moment. He scooted closer to Donna, and pressed it to her neck.

With the soft hiss of release the shaking stopped. He reached out a hand to touch her, and her skin was cold, colder than his. His fingers sought her pulse but, despite the frantic search, he couldn't find one.

The TARDIS was blowing warm air on him, but he stood suddenly and shouted, "You killed her!"

He heard the TARDIS hum and the warm air turned cold in her anger. She was trying to help, he knew. Donna was going to die, and this just ended her agony.

He watched her on the bed, his hearts breaking, and he was so unsure. Finally he decided the best thing to do, while he could do it without a Donna vampire running around the TARDIS, was research. The TARDIS had said there was nothing on board that would cure her, not that there was nothing that would cure her.

There had to be something somewhere.

He shuffled back to her bedside, leaned over and placed his hand on the top of her hair. She was so still, and it brought tears to his eyes. It didn't matter if she was coming back, because wasn't she still lost. Her eyes wouldn't be that kind blue; her laugh wouldn't be that of melody. What would she be?

He kissed her pale, cool head, and stood back up.

He walked from the bedroom, closing the door and locking it behind him. He didn't want her escaping while he wasn't looking, and hoped she wouldn't be aware that he had locked her in.

He headed to the library, asking the TARDIS to watch her, while tears ran down his face.

DW

The pain had been so bad, worse than she would have thought was possible, but she was aware. She could hear the Doctor, but she couldn't respond. She wished she could tell him that she would be okay, anything to ease the pain that had overtaken his voice.

She shouldn't have run outside, she knew that he hadn't meant what he said. He wasn't trying to hurt her, he was always telling her how brilliant she was, so why did she take it so much to heart? She supposed it was because she was reminded of once again, how much lower than him she would always be.

She hadn't meant to feel this much for him, but now that she did it killed her that he would never feel the same. His hearts belonged to someone else, and she didn't have a chance.

That was why she had run, why she had been so stupid. So really, this was all her fault. And if she could use her mouth she would tell him so.

Then suddenly the pain was gone, and she felt different. There wasn't the familiar thud inside her chest, and she wasn't breathing, but she was still there.

She was! She could feel herself, she could still think. She was thirsty, like she had walked through the desert without a drop of water, but she was still her.

It was all confusion; she didn't know what had attacked her. The Doctor told her something about…vampires? She thought that was what he had said, had that been what had happened?

She thought of the Doctor, as a new feeling swept through her. It threatened to overwhelm her, and that thirst became something worse than that simple desire. She thought of water, of finding a big glass and drinking it, but the thought made her stomach turn.

It wasn't what she wanted, and then she thought of red, just the color red and she felt her body tremble with want.

This wasn't good; this was wasn't good at all. Where was the Doctor? She needed the Doctor; if she could just see him she would be okay. She tried to call out but her throat was dry, too dry.

But she managed to pull her eyes open, the room was dark but she could see very well. If her heart was beating, which it wasn't, it would be beating quickly. She pulled herself up off her bed, she was in the TARDIS, but she was alone.

Where was the Doctor? How could he leave her?

She got her lungs to inhale, but understood that she didn't need the breath. Everything was red, her unnecessary breath was red, her thoughts were red, and every quiet step was red. She could think of nothing else, but she then she smelled it. Blood, and she tried to fight it, she knew that it was the Doctor.

And the Doctor was everything, her whole world.

She was at the door, without the decision to do it, pulling at the handle. It was locked and something dark within her chuckled.

"Nice try, Doctor," she whispered.

Her tongue was dry; maybe she could just have a sip, which would be enough. She was shaking with the effort of trying not to hunt him down.

Her hand was still on the door, and with what seemed like no effort, she had pulled it off the hinges.

She heard the TARDIS humming, and for a moment she felt bad. She wanted to apologize, but the smell was floating into her nose, consuming her whole world. A feral smile drew her lips up, and she left her room.

The hunt was on.