"Definitely," the Doctor agreed as he dashed to the console and began slamming buttons and levers to set the TARDIS in motion.

He didn't know how much he could trust Lucy. He wanted to trust her, he wanted to believe she'd just been corrupted by the Master and she was, deep down, a good person. He wanted to believe it, but he wasn't sure he could. But he knew he couldn't just leave her to whatever fate the people of Earth would've had planned.

"Something very dangerous and very powerful, to expel so much energy towards Earth." He grinned over the console. "Hold on tight."