"So there was a teleport device used here?" Rose asked.
"Yep."
They had been standing next to the heat shimmers for about five minutes and Rose was already feeling warmer but a bit bored.
"Where does the teleport go?"
"Underground."
"How can you be sure? Oh, right," Rose said as the Doctor waved the sonic screwdriver at her.
The Doctor bent down and started to examine the heat shimmers with his screwdriver.
Back. Up. Circuitry. Working. Fully.
"Oh, what a surprise. You kill someone and the job suddenly gets done," the cool voice laughed. "What was the problem in the first place?"
Loose. Connections.
"Loose connections, huh. Kill the electrician."
Confirmed.
"What are you doing?" Rose asked ten minutes later when she was still standing around and the Doctor hadn't even moved.
The Doctor sighed and stood up. "I'm trying to find the ultra-frequency button."
"Button?"
"What's wrong with 'button'?"
"Nothing. What's the button do?"
"Well, you go into the right part of the heat shimmers and that's the teleport. You can tell which bit of the heat shimmers is the right bit by measuring the ultra-frequency."
"Which you can do with your sonic screwdriver."
"Yes. But, someone's turned it off. Either no ones been using it for a while or someone," he glanced downwards, "doesn't want me down there."