Four days earlier

The Doctor flipped through a book. He sighed and tossed it to the ground casually as he finished.

"Bad ending." He said simply.

The TARDIS made a noise. A heavy, breath-like noise.

The Doctor raised an eyebrow. The column in the center was still frozen, still in position.

"That's odd."

He walked over to the center console, pressing buttons, but the noise did not stop.

"Hmm…" He turned around.

And found himself facing a man.

He stumbled back. The man was tall, with dark hair and black clothes. He looked exhausted, and his breathing was heavy. Inside his eyes, light was twisting, as though it were a living creature that was in agony.

"She's not going to put up with me for long. There isn't much time." The man gestured to the TARDIS. "Listen very carefully.

"In two days, you're going to give this to Donna Noble." He pulled something out of his pocket. "And she is going to stab you."

The Doctor looked as though he would protest, but the man raised a hand, cutting him off.

"No time! You won't die, I can guarantee that. When she stabs you, you're going to lose all memory that I was ever here, or how the knife got in your chest. After that, you're on your own."

He handed the object to the Time Lord. It was a knife. A large, sharp knife.

"At that point, I'll be there. And neither of you will remember a thing, understood? I'll make you forget."

The Doctor tried to open his mouth, but the man dematerialized in front of him.

He stood, staring. The knife in his hand was the only proof that the man was there at all.

Two days later.

Donna stared at the Doctor. "NO! Doctor, this is insane!"

"That man looked into the heart of the TARDIS." The Doctor replied coolly. "He knows something about the future."

"But that doesn't mean I should stab you! We need to re-think this!" Panic was flashing in her eyes.

The Doctor looked at her. His eyes were smoldering softly, gazing intently into Donna's own.

"Donna… oh, Donna, please. Please, I need you to trust me." He placed his hands on her shoulders. "Please."

She looked down at the knife. "You'll be ok afterwards?" Her voice cracked.

He nodded.

"And neither of us will remember?"

Another nod.

She took a deep breath, then wrapped her arms around him. "I'm sorry, Doctor. Please believe me. I'm so so sorry…"

He gently stroked her hair back. "You haven't done anything yet."

"Doctor, please…"

For a moment, there was silence.

Finally, Donna broke away from the hug. There were tears in her eyes. "Are you ready?"

He shrugged. "As ready as I'll ever be."

She nodded and raised the knife. She closed her eyes and tears streamed down her cheeks in a steady flow. Donna Noble was no killer. And, despite how many times she'd slapped The Doctor, she really did care about him.

She brought the knife down.

The Doctor cried out in pain, and Donna opened her eyes. As soon as she did, she wished she hadn't.

Blood was pouring from the Time Lord's chest. He gasped repeatedly, trying to get as much breath as he could.

She ran to his side, helping him as he almost fell to the floor. She sobbed. "I'm sorry, I'm sorry, I'm sorry…"

He smiled painfully and nodded. "It's ok… It's ok…"

A hand rested on Donna's shoulder. She jumped and looked upwards at the owner.

It had to be the man that The Doctor had talked about. Light was flowing in his eyes, a sun against a black hole.

"You did what had to be done." He said coldly. "Now stand back."

Donna did as told. The man placed his hands on The Doctor's shoulders.

The Time Lord felt his DNA shift and change. It continued to do so even as the other man lifted his hands away. Light flowed in between the two. Pure time energy sealed his DNA inside itself, making him a part of the vortex.

The Doctor looked at him in shock and fear as he felt himself moving from this point in time to another. Slowly, his memories began to die, until everything from up to four days ago was nothing but haze and smoke.

He opened his eyes. He was in some sort of forest. Shadows distorted images, and his vision was fogged over.

There, standing in that, was a man. His eyes widened, but it was more out of fear than shock.

And he started running.

The Doctor stood, trying to ignore the pain in his chest. He needed help. And this was the only person who could help him; he was certain of it.

And Hiro ran from the Time Lord, equally certain that he was a monster.

But Donna was still remembering. She still remembered what she had done.

"You promised I wouldn't know!" She told the strange man with the glowing eyes. "You promised!"

He nodded. He was still staring at the spot where the Doctor had been moments before. "And you won't remember anything."

He placed his hands on her head. She was forced to look him in the eyes as he did so. He closed his eyes, and she felt everything that had happened begin to disappear.

Unconsciousness claimed her, and she collapsed to the ground.

The man stood and disappeared. His job was done. The DNA of both The Doctor and Donna had been changed, set into flux, shifting the two of them in and out of the time vortex. The Doctor was following Hiro with a knife in his chest, and Hiro was running, afraid of the monster behind him.

Time was doing what it was meant to do.

Now, he was to return, to go back to the Donna Noble he knew…

In the shadows, Sylar watched in fascination. His eyes were all-too-dark, not filled with the strange, ethereal light.

But those eyes had seen what had happened. Those eyes had seen a man disappear, had seen power that he'd never known of before.

He walked over to the unconscious red-head and smiled. This could work out very nicely for him.

A/N: Ok, I know it's a very short chapter. I just wanted to clear a few things up before I continue with the story. The next one should be longer.