With a loud sigh, Evie exited the TARDIS, shooting the Doctor a despairing look and shaking her head at him. He furrowed his brow, but followed, locking the door behind him. He was obsessive over that action – worried that someone would break in while she was unattended.

"Where are we?" Evie repeated.

The Doctor looked around, thinking before he answered her question. Evie took this to mean that he didn't have a clue where they were.

"Where are we supposed to be?" She asked with a sigh.

"Well… we were supposed to be going to Sto. I had a friend from there, Astrid, I think I mentioned her?" He babbled, trying to distract the teenager from the fact that he didn't actually know where they had ended up. She was staring at him with a hand on one hip, her head tilted slightly and a clearly unimpressed expression on her face.

"Right… but this isn't Sto?" Evie clarified. The Doctor shrugged. "What…?"

"The co-ordinates were right…" He muttered.

The teenager had to take several deep, steadying breaths to combat her urge to punch the Timelord in the face. Then she thought logically about the situation. She had asked the Doctor for an adventure and here it was. He'd kept his word. As this realisation hit her, Evie threw her arms around the man and hugged him tightly.

The Doctor was taken aback by her action. He'd been expecting something more negative. But he wasn't going to complain. If she was happy then he was happy. Grabbing her by the hand he pulled her along the tunnel that led from the cave they were in.

The walls were made of a strange, red stone. From the looks of them they were damp; they were glistening as the light from the Doctor's torch – where he'd produced that from Evie wasn't sure – caught them. Every now and then the beam would fall on different coloured rocks, reflecting colours back at them.

"What's Sto like then?" Evie asked. If, by some miracle the Doctor had managed to get them to the right place, she wanted to know what she was dealing with. And, if she wasn't going to get to see it, she may as well know what she was missing out on.

"It's… it's a planet in the Cassavalian Belt with a population of near-humans." He enlightened her, keeping his eyes firmly fixed ahead of them. Without realising he'd done it, he'd pushed Evie behind him, subconsciously protecting the teenager from any unseen dangers.

"What's a near-human?"

"Basically a human." He agreed with a nod. "But there are also Zocci, Cyborgs and Androids."

"Zocci?" Evie asked, raising her eyebrows. The Doctor always forgot that all this was new to her.

"Like a small, red person with spikes all over their heads. They're humanoids, but don't look much like us."

"Right…" Evie raised her eyebrows slightly at the vague explanation of the creature. The Doctor wasn't brilliant at explaining things, but that was one of his worst yet.

They'd reached the end of the passageway and light was visible in the distance. Eagerly the pair made their way towards it, wondering where they were going to end up. Blinking at the sudden change in light levels, Evie followed the Doctor outside.

Sto was similar to Earth. Amazingly similar. They walked out of the cave and onto a sort of plain. The cave tunnel led from a hill, upon which was built some kind of watch tower. Without thinking, the Doctor grabbed Evie and pulled her back out of sight into the mouth of the tunnel.

"Can't be too careful." He said as the teenager rolled her eyes again. "We don't know who's in there, or why."

"Why do you always see the worst?" She asked, leaning forwards and craning her neck to look over the edge of the cave and up at the watchtower high above them.

"Experience."

"Oh, sweetie," Evie said, shaking her head pityingly, "that's why inexperience is so important."

Before he could stop her, the teenage girl had slipped from the cave and was clambering up the almost sheer face of the hill, heading for the building at the top. The Doctor tried to grab hold of her legs, but they were just out of his reach.

"Evie!" he hissed, furious at her recklessness. She turned and winked at him, before continuing with her climb. Exhaling sharply the Doctor realised that the only thing he could do was follow her.

Luckily there were hand and foot holds so he was able to get a good grip on the rock face. The teenager had left him behind but, the Doctor was glad to notice, she had the sense to wait for him on a sheltered outcrop of rock, just hidden from view of the top. He pulled himself up beside her and raised his eyebrows. She, in turn, rolled her eyes knowing exactly what he was thinking. Not in the mood for a lecture, she turned and made to continue the climb. The Doctor grabbed the back of her checked shirt and pulled her back down.

"Wait!" He commanded, pulling out his sonic screwdriver and clamping it between his teeth, preparing to start climbing the rock once more.

"Ooh, action man." Evie muttered sarcastically, annoyed that he was treating her like a child. He turned and fixed her with a look that made the teenager pull a face, but shut her mouth, concentrating on where she was putting her hands and feet instead.

Just before the top of the cliff, the Doctor stopped. Evie didn't, smacking her head on the bottom of his foot. She glared at him, unable to rub the sore patch in case she fell. He put a finger to his lips, wobbled and replaced the hand on the rock.

Unable to see what he was looking at, all Evie could do was wait until he hoisted himself over the edge and reached down a hand to help her up. Ignoring it, she scrambled over the edge, dusting her jeans down. At her blatant refusal to be helped the Doctor smiled a little. She was determined to be independent, something that he admired. But if that independence got her into trouble… well, he'd have to make sure he was there to sort her out.

"Come on." He said in a low voice, pointing towards the watchtower. A small huddle of people was standing outside it, luckily looking in the opposite direction. Crouching so that they were less conspicuous, Evie and the Doctor moved quickly towards them, dodging behind a stack of metal crates conveniently placed a couple of feet from the entrance.

While the Doctor was watching the happenings around the entrance to the watchtower, a large square building made of glass and steel that glinted in the evening sunlight, Evie was rummaging around in the boxes they were hiding behind. She pulled a confused face as she saw what was inside.

"Doctor, what's this?" She asked, pulling a metal arm out and waving it around in the air.