It sounded so simple when the Doctor explained it. But, to Sylar, it was anything but simple.

Sylar gently placed his hand on the panel that covered the heart of the TARDIS. The time machine wasn't taking his presence too kindly; the lights had dimmed considerably as soon as he'd walked thorough the doors.

"There are some… risks." The Doctor swallowed. "You'd have to get rid of the time energy as soon as you possibly could. Too long and…"

"I die." Sylar cut him off.

"Or go insane."

"I can live with that." Sylar gently stroked the panel. The TARDIS's lights flickered unhappily at his touch.

The Doctor didn't seem too thrilled about it, either. "You're the only one who has a chance. I saw it once and…well, I had to regenerate."

"You cheated." Sylar said with a smile.

"You could say that." The Doctor swallowed. "But only Time Lords could manage it, and even then, I don't know if I could do it twice. Humans would burn. It would be too much for them…"

"But for a hero…" Sylar looked longingly at the panel, wishing to tear it open then and there, desperate for the secrets inside.

"I warned you, Sylar. You may not be able to handle it. In fact, I highly doubt you will. But… it's the only chance."

"And if I refuse?"

"Will you?"

"No. But if I did?"

"Then things would get very bad, very fast." The Doctor looked at him seriously. "If my theory is correct…"

"Than your DNA is shifting you in and out of the vortex, ripping holes in the fabric of space and time." Sylar recited perfectly. "I know."

There was silence for a minute.

"This could be incredibly dangerous for you, Sylar…"

"Are you trying to convince me out of it?"

"No. I'm just… warning you. I'm not sure if this is the best idea. If you go insane… Well, I won't lie to you. You'd be… unstoppable."

Sylar's eyes gleamed for a second, but he managed to control it. "I know."

"It's a very dangerous…"

"I know." Sylar was trying not to betray his irritation, but it was growing more and more difficult. The warnings were starting to become repetitive. Though he supposed it would be difficult for The Doctor to do this; to give a serial killer all of this power, even for a second…

The Doctor looked at him for a moment. "You can't keep it, Sylar."

Sylar didn't reply. He knew this, of course. Whatever was locked in the heart of the TARDIS was too powerful for Sylar to contain. Eventually, despite his non-human nature, he would die. Or go insane.

But he knew something that The Doctor did not.

After a moment, he nodded. "I know."

There was silence again.

Finally, Sylar spoke up. "What happens… when it's over? What happens to me?"

"Assuming you survive." The Doctor added unhelpfully. "We'll just have to figure it out as we go along."

Sylar nodded very slowly. At last, he turned to face The Doctor, tearing his eyes away from the panel.

"Shall we, then?"

The Doctor looked at him warily. "Why are you doing this, Sylar? Why are you agreeing? It's not for the power; you'll be giving that up." The Doctor stepped towards him. "So what is it?"

For a moment, the Time Lord and the hero just stared at each other. Finally, Sylar smiled.

"Curiosity." He replied. "I know how many things work, Doctor. I just want to know."

The Doctor looked at him, then nodded, accepting the answer.

"Very well, then." He turned his eyes to the panel. He winced; this was clearly hard for him to do. He gestured towards it, and Sylar smiled. No more words were spoken as Sylar walked over to it.

Sylar held out a hand, just above the panel. His fingers flexed as telekinetic energy pulled at the panel with increasing force.

Sylar stayed like that for a long time, his eyes narrowing in concentration. After a minute that felt like an eternity, Sylar gasped.

"I thought you said a truck opened it." He shot an accusing glare towards the Doctor.

"For Rose." The Doctor replied, shrugging. "The TARDIS knew her. Probably helped her out." His eyes flickered from the panel to Sylar's face. "It might be more difficult for you. The TARDIS doesn't exactly like you."

Sylar glowered at him. "Thanks for the warning."

He raised his hand again.

For a moment, nothing happened. The panel remained where it was, immobile, solid, with no hope of being opened.

And then it started to shake. Sweat beaded on Sylar's forehead as he focused on it. His muscles strained, and the TARDIS lights flickered.

The panel rattled. The TARDIS console sparked, but Sylar didn't seem to notice. His eyes were locked on the panel, every thought focused on opening it.

His other hand joined the first as he concentrated, the energy pulling harder and harder.

And then, so suddenly it was almost as though it hadn't happened, the panel opened. A pale, glowing light flowed around it, trying to remain inside the TARDIS.

Sylar took a glance at the Doctor, who nodded quickly, panic flashing in his eyes. The serial killer stepped towards it, his heart racing.

And he stared, straight into the light.

The Doctor wasn't sure why he was doing this.

His hearts were racing, thumping unevenly as Sylar stepped towards the now-open panel.

The light went directly from the TARDIS and into Sylar's eyes. It flowed and danced around him like a living thing.

For a brief second, The Doctor's vision was completely blocked by white light. He closed his eyes, then opened them again as the light vanished, trying to find Sylar.

The Doctor's eyes locked on the shuddering form a short distance away from him. Sylar was leaning against the TARDIS console. The panel was still open.

The serial killer looked up. Light was dancing in his eyes, floating and twisting inside their dark depths.

"Sylar…?" The Doctor said the word very cautiously.

The hero looked at him curiously. His breathing was harsh and ragged. Sweat glistened on his skin, and there were dark circles under his eyes.

The Doctor swallowed. He knew instantly that something was wrong; it hadn't been like this with Rose, not this quickly…

"I… can't…" Sylar's words were strained.

The killer took a deep breath. It rattled and grated in his lungs.

"It's… my… fault…" He whispered, his words cracking.

The Doctor took a cautious step towards him. "What happened, Sylar? Why is my DNA this way? What about Donna?"

Sylar looked at him. "Donna's DNA… and yours… my… fault!" He gasped, a hideous sound that made The Doctor wince.

Sylar stumbled over to the panel again. He collapsed in front of it, and stared deep into its heart for the second time.

The light traveled away from his eyes once more. It went back, to its proper place in the universe.

When the light vanished, the panel clamped shut. Sylar gasped again, then collapsed to the floor, lying flat on his back. His breathing was heavy as he did so.

"Sylar?" The Doctor asked. He came over to the hero.

Sylar's eyes were closed. Slowly, he sat up, not bothering to open them, as though he was still in too much pain to do anything that wasn't necessary.

"It's me." Sylar whispered to the Time Lord. "It's my fault that your DNA is in flux."

The Doctor raised an eyebrow. "Your fault…?"

He trailed off as Sylar smiled. It was a strange smile, a triumphant smile. Slowly, it grew into a laugh. A laugh that was so hard, so cruel, so hideous that The Doctor couldn't help but cringe.

"Oh, Doctor." Sylar coughed in the middle of his laughter. "You don't get it, do you?"

The Doctor stared at him.

"I… know how things work." Sylar coughed again. "How else… would I be… this powerful?"

The Doctor looked at him with wide eyes.

Sylar's eyes were still closed, but as he spoke, he opened them.

The Doctor stumbled backwards. "Impossible! You put it back! You gave it back!"

But it was all too true. Sylar's eyes were still glowing, still alight with the unnatural, living light that had been in the heart of the TARDIS.

"You can't possibly understand." Sylar rolled his shining eyes. "Don't you see, Doctor? I know how things work. I know how your TARDIS works." His smile grew ever wider.

"So I don't need your TARDIS anymore."

Realization slowly dawned on the Time Lord's face. He swallowed, his hearts pounding strangely.

"Remember that little regenerist I told you about? Claire Bennett? Remember how I told you that she didn't die?" Sylar laughed again. "I don't take abilities, Doctor. The death is just a side affect." He coughed. "No, I just need to see. And then I know. And then the ability is part of me."

"So you know how the TARDIS works." The Doctor completed, horrified.

The serial killer laughed. "Exactly, Doctor! I don't need your TARDIS, don't you see? I am a TARDIS!"

Donna didn't know what happened.

One moment, a furious-looking Molly was telling her that she was no where.

And the next, the world was white.

Donna stared through the white, whirling around again and again, but there was nothing to see. There was nothing and no one in sight.

"Oi!" She called out, unsure exactly why she was doing so. "Anyone there?"

Something coughed behind her. Donna whirled around again.

Her eyes widened.

"Hello, Donna." Sylar smiled at her, a disgustingly sweet smile that she just wanted to wipe off of his face. His eyes were glowing; literally glowing. The light twisted and floated in his eyes strangely.

"Sylar." Donna's eyes narrowed. The last time she'd met this man, she'd been locked in a room, unable to do anything to defend herself as the gash on her forehead grew larger.

This time, things would be different. Donna was tired of being helpless.

Sylar looked at her. "I suppose your wondering where you are."

"Not really. I'm just enjoying the scenery." Donna bit out the words sarcastically.

Sylar's smile widened. "You're brave, human. I'll give you credit for that."

"Travel with The Doctor for a while and that's what happens." Donna rolled her eyes. "You meet so many monsters, you kind of get used to them." Her eyes locked on him. "Even if they look human."

He chuckled. "So I'm a monster now, am I?"

"I wonder." She rolled her eyes. "That's a real hard one to figure out, isn't it?"

He laughed. "Like I said. Brave."

Sylar moved a hand, and The Doctor was thrown backwards against the TARDIS. His head slammed into the side, causing sparks to fly from the time machine.

"If you don't mind…" Sylar said calmly. "I have something I must finish."

Sylar dematerialized in front of The Doctor, though he was lacking the noise that the TARDIS made.

The Time Lord closed his eyes sadly. "Oh, Sylar." He stood very slowly, then gently stroked the TARDIS console. The lights had brightened with the departure of the serial killer.

"I really tried." The Doctor whispered. "I really did."

He sighed and started pressing a few buttons slowly. He knew that Sylar had seen the whole of time, for just a minute. That was what he had given back.

And yet, he'd also seen what was inside the TARDIS. How she 'worked,' in his terms. And so he knew how to travel in time and space.

The Doctor looked down and picked up the TARDIS's phone. He punched in a number, then placed it to his ear.

"Hello?"

"Peter? It's the Doctor. Is Donna there?"

"Um… Doctor… we tried… but she just…"

"Disappeared." The Doctor completed for him calmly. "So that's what he's doing…" He trailed off and thought for a moment. Finally, he spoke again. "Peter, I need you and Matt to come with me. It's the only way we're going to stop Sylar."

Slowly, he explained everything. While he did that, he walked around the TARDIS, pulling levers and pushing buttons. The time machine came to life, and she lurched into the vortex.

Finally, The Doctor hung up. He sighed again.

"I had to give you a chance."