The Doctor wasted no time in rushing past the young man and soon enough they were at the crater. He kneeled down beside the cool water and dipped the small object into the liquid, keeping it there for a while. He mumbled something to himself as his back began to twinge again, but he tried to ignore it. 

Even though he wasn't looking at Leander, he quietly listened to what the young boy was telling him. He was happily describing his past when suddenly, Leander mentioned something about wanting to meet an extra-terrestrial being. Little did he know, he was stood a couple of meters away from one. 

The small object in the Time Lord's hand suddenly began to heat up and the Doctor could feel it's outer core begin to get so hot he could hardly keep a hold of it. And this only meant one thing. One very bad thing. He got to his feet slowly and turned towards Leander who was lying on the ground. The Doctor sighed. 

"I'm sorry Leander, I'm so sorry, but we're in danger." The Doctor stated grimly, taking a few steps towards the young man. "This-" The Doctor held up the small and now warm object in his hand. "-is a Slitheen tracking device, which means Leander, there are aliens very nearby."