The meanings of words can change over time to refer to something entirely different to their origins.

So it was with possible and impossible.

It used to be impossible for a person to fly. Now it was possible. It was once impossible for someone to run faster than a car. Or a train. Or a bullet. Now, those things were commonplace. When the words were flipped on their heads, and dropped out of use because no one really knew in what context to use them anymore, impossible became the new possible.

But, still, there were rules. Or possibilities.

It was not possible for a person to have more than one power. It just didn't happen. You had what you got and that was that. Cells were altered, abilities – or an ability - were gained. You couldn't change your power, so had to accept it. It was the only one you were going to get.

So how had Bren, who could alter her appearance to look like and become as thin as a wall, propel a child's broken body a dozen feet?

She hadn't. She couldn't.

But her eyes.

"We need to get out of here," she said. "I need to think."

"OK," Thomas agreed.

What else or where else could he go? She might not want him around after what had happened, but until she said so, he had no choices apart from following her wherever she went.

"Come on," she said.

Thomas swallowed down the feeling of relief. She'd invited him along. That meant she wasn't done with him yet. He'd get his chance to explain and to perhaps alter the prejudices she wouldn't be able to help feeling.

She turned to leave and he moved to follow her.

"Keep up," she said.

He didn't have the chance to respond. She was on the move.

Luckily, finally, Bren's ability wasn't one of strength or speed. She might have been older than him, but he found it easy to keep up. Running from abuse had honed his skills and, as a result, they ran together, neck and neck. It was only when Bren turned corners or suddenly scaled a fence that she edged ahead. He soon caught up.

When they'd reached the entrance to the alley, they peered out. Thomas knew he was being hunted. Bren was checking that Stan wasn't there and hadn't brought reinforcements. The street, apart from the usual amount of people going about their business, was clear. Without warning, the girl stepped out and started walking. He fell in with her, matching her brisk pace.

"Where are we going?"

"You'll see," she answered. She wouldn't be pushed on the location any more than that, so he left it and concentrated on keeping up and keeping an eye out for them.

They came to a thin gap just before the entrance to a park. A high wall ran along the edge of the part, separating park and pub by a matter of inches. It was a tight fit to squeeze through, but that was exactly what Bren wanted them to do.

"This way," she said, saying the words at the same time as she stepped sideways.

Thomas had already walked a few steps on before he'd realised what she meant. She was easing herself into the gap and he could see her body adjusting its shape to allow her in. She flattened, becoming wider and thinner. She was moving into the space easily. He thought he'd have much less chance to get through it as smoothly as she was able to, but he followed nonetheless.

He was right. He wasn't a big child by any means, but he still found it difficult to push himself in. He found that, if he turned his head to the side and exhaled as fully as he could, he was just able to get himself in. While her movement was fast, his was slow and painful. He could feel sharp spurs of brick digging into his back and his chest. One caught his cheek and drew a long scratch across it. He cursed under his breath but continued. He had no choice, he was in there now. He couldn't stop and stay still and nor could he go back. He had no way of turning his head back to watch where he was going and, when he did attempt it, he found he kept catching himself and his clothes on the bumps and lumps of the bricks.

Time dragged on. Thomas knew how big the park was and knew it to be huge. When younger, he'd spent many an hour playing there with Billy or his father. That was before, of course, he became an outcast. For the moment, he was no longer that. He felt he belonged to something, even if it was only a fledgling friendship with the girl.

"We're here," said Bren. Her voice was husky with exertion. Holding her altered form for so long was tiring and, though she was an adept, it still took its toll.

Thomas stopped, but frowned. He'd expected 'here' to be the other end of the channel. The far side of the park. It wasn't. Looking past Bren showed they were still some way off. So, what did she mean?

"Where?"

"Here," she repeated.

Her body shuddered and rippled as front became back. It took just a few seconds for her to turn around, but it was something Thomas had no way of doing. She looked at him to speak and he saw the fire circling her pupils. He was more convinced she had thrown Stan across the alley. She must have done.

"Look," Bren said. She was pointing, but Thomas couldn't quite see what at.

"What is it?" he asked.

Bren pointed again.

"There."

Thomas gritted his teeth, which only served to make his cheek sting more than it already was, and turned his head as far as he could.

There was a mark on the wall. No, not a mark. A drawing.

"A worm?"

"Yes, a worm."

"What;'s that me... Erm... So?"

"Sshhhh," Bren said. "Stay quiet until I tell you otherwise."

Thomas opened his mouth to protest, but a stare and raised eyebrow from her stopped him. He nodded slightly.

Bren put her forefinger onto the drawing of the worm. It was blue and looked to have a scarf around its neck. It seemed familiar, though he couldn't place it. He had no time to think about it, as, when Bren pressed, there was a series of hushed clicks and the sound of bars moving and locking into place. Or unlocking.

The area of wall around the worm suddenly slipped inward and soundlessly dropped out of sight. Bren reached into the resultant hole and fumbled about inside. There was another click and the lower portion of the wall swung in. Bren stepped inside and gestured to Thomas to follow.

When they were both inside, Bren pushed the bottom part of the wall back in place. With silent smoothness, the section that had the worm drawn on it slid back up and into place, taking the light with it.

Thomas stood in total darkness, feeling exposed. He couldn't see the girl or his own hand in front of his place.

"Bren?"

"I'm here," she said, but she was no longer beside him.

He heard a switch being activated. There was a brief pause, then the darkness slowly receded as a bulb high on a vaulted ceiling brightened. Bren was standing further away, next to a light switch. She smiled at Thomas, but the smile lacked any real sincerity. He couldn't blame her. She would be as concerned as anyone. Were their roles reversed, he'd be the same.

"Where are we?"

The room they were in was barely a shell. Only one wall had plaster still attached to it, and that was cracked and missing in parts. On another, the wooden struts that should have made its innards were on display, the plasterboard that would have been attached missing. The room beyond was mostly in darkness, with the bulb in their room not quite reaching much beyond the wooden barrier. On the remaining two walls, one of which housed the door mechanism they'd just used, Thomas could see the large breeze blocks that made the inner lining of the outer brick surface.

Against the first wall was a low sofa. The springs in it were obviously only just able to carry out their function. The three cushions that comprised the seating area were dipping in odd places, making it look decidedly uncomfortable to sit on. In the centre of the room was a coffee table. It was bare apart from a single book. To Kill a Mockingbird. The book looked to have been well read, but it wasn't one Thomas was familiar with. It looked too serious for his tastes.

Bren walked over to the sofa and fell into it. The springs groaned, but Bren didn't seem to notice.

"Does it matter?" she asked, shrugging her shoulders.

"Yes," he answered. He'd followed her blindly, so he wanted to know he wasn't a fool to do so. "What is this place?"

"Home."