Okay, so for Charlie this takes place just before the episode detained while for Susan it is while she is leaving the school in the unearthly child. I don't own doctor who or class, though I wish I did.

Charlie stared at the girl who had appeared through the year in time and space. The girl stared back at him, seemingly just as surprised as him. Meanwhile, the crack in the wall glowed brightly, which would have attracted attention if there had been anyone here. But everyone had left and Charlie was currently waiting for Quill to come back and take him to detention for a minor breaking of the rules.

"Who are you?" Charlie asked, becoming wary of the girl. Since the Doctor himself asked Charlie and his friends, along with Quill, to protect the school from the things that come out of the portals to another point in the universe and history, Charlie has learned not to trust anything that came out of the "bunghole of time" as Tanya called it.

"Who are you?" the girl asked back. At first, Charlie was tempted to ask her again, but then he saw the fear in her eyes. And he realized that whoever this girl was, she had no idea what was happening.

"My name is Charlie. Charlie Smith." he told her gently. "And what's your name?"

"Susan Foreman." she answered. "What happened? One second I was leaving the school, with the book miss Wright let me borrow, the next here I am here."

"Okay." Charlie said hesitantly, as he tried to figure out what to do. Obviously Susan was human and judging from her clothes not from this time. Logically going back through the portal should take her back to her time. But how could he convince her to go through it?

"Okay, listen," Charlie began, "this is going to be a shock, but you went through a tear in time and space. This is Coal Hill Academy and the year is 2016. I am an alien who goes to the school here."

"Seriously?" Susan asked after a moment, leading Charlie to nod. A few seconds past, before Susan burst out laughing.

"Look, I know it sounds insane but-" he tried to say, but he was cut off quickly by Charlie.

"No, it's not that. It's just that I'm an alien as well!" Susan said quickly. "And I go to school here!"

"Really?" Charlie asked, surprised by the knowledge.

"Yeah! I live with my grandfather and go to school here in 1963. Except it was called Coal Hill School then." Susan told him.

"Yes, they changed it apparently some time before I came here." he replied. While the situation was surprising, he was glad to meet someone in the same situation as him. "It's weird isn't it?"

"What, that they changed the name?" she asked.

"No. Living on Earth. Pretending to be human and fitting in. Using a name that isn't your own."

"Yeah." Susan said with a nod. "My father doesn't really understand why I like living on Earth so much. Or humans for that matter."

"The person I live with doesn't really like humans either. She doesn't see them as people." Charlie said, becoming sad as he thought about the people Quill tended to hurt.

"But they're amazing aren't they?" Susan said with a smile.

"Yes. Indeed they are." Charlie agreed, as he thought about his friends and boyfriend, people he cared about more than anything else in the world. Suddenly, the tear behind Susan began making a noise. "Looks like it's closing. You should go through before it does."

"Are you going to be okay?" Susan asked him as she edged closer to the portal back to her own time.

"I'll be fine." Charlie said with a nod. "Are you?"

"Yeah, I think so." Susan replied. "Hopefully I'll see you again Charlie Smith."

"Same here Susan Foreman." Charlie said with a smile, as he watched her step through the portal back to her time. As she did, the portal closed and disappeared.

Tell me what you think and if there are spelling mistakes.