Caitlin stood before the door to her new apartment, staring, and suddenly realized where she was. She had no idea how she got there. The last thing she remembered, she'd been in the alley. Somehow, she'd got herself back home.

She remembered, though, every second of what happened in that alleyway. She tried to erase it from her mind, but couldn't. She looked down at her arms and hands, expecting to see them look different - but they were normal. Just as they had always been. The rage had swept through her, transforming her, then had just as quickly left.

But the after-effects remained: she felt hollowed out, for one. Numb. And she felt something else. She couldn't quite figure it. Images kept flashing through her mind, images of those bullies' exposed necks. Of their heartbeat pulsing. And she felt a hunger. A craving.

Caitlin really didn't want to return home. She didn't want to deal with her Mom, especially today, didn't want to deal with a new place, with unpacking. If it weren't for Sam being in there, she may have just turned around and left. Where she'd go, she had no idea - but at least she'd be walking.

She took a deep breath and reached out and placed her hand on the knob. Either the knob was warm, or her hand was as cold as ice.

Caitlin entered the too-bright apartment. She could smell food on the stove - or probably, in the microwave. Sam. He always got home early and made himself dinner. Her Mom wouldn't be home for hours.

"That doesn't look like a good first day."

Caitlin turned, shocked at the sound of her Mom's voice. She sat there, on the couch, smoking a cigarette, already looking Caitlin up and down with scorn.

"What did ya, ruin that sweater already?"

Caitlin looked down and noticed for the first time the dirt stains; probably from hitting the cement.

"Why are you home so early?" Caitlin asked.

"First day for me, too, ya know," she snapped. "You're not the only one. Light workload. Boss sent me home early."

Caitlin couldn't take her Mom's nasty tone. Not tonight. She was always being snotty towards her, and tonight, Caitlin had enough. She decided to give her a taste of her own medicine.

"Great," Caitlin snapped back. "Does that mean we're moving again?"

Her Mom suddenly jumped to her feet. "You watch that fresh mouth of yours!" she screamed.

Caitlin knew her Mom had just been waiting for an excuse to yell at her. She figured it was best to just bait her and get it over with.

"You shouldn't smoke around Sam," Caitlin answered coldly, then entered her tiny bedroom and slammed the door behind her, locking it.

Immediately, her Mom banged at the door.

"You come out here, you little brat! What kind of way is that to talk to your mother!? Who puts bread on your table...."

On this night, Caitlin, so distracted, was able to drown out her Mom's voice. Instead, she replayed in her mind the day's events. The sound of those kids' laughter. The sound of her own heart pounding in her ears. The sound of her own roar.

What exactly had happened? How did she get such strength? Was it just an adrenaline rush? A part of her wished it was. But another part of her knew it wasn't. What was she?

The banging on her door continued, but Caitlin barely heard it. Her cell sat on her desk, vibrating like crazy, lighting up with IMs, texts, emails, Facebook chats - but she barely heard that, too.

She moved to her tiny window and looked down at the corner of Amsterdam Ave, and a new sound rose in her mind. It was the sound of Jonah's voice. The image of his smile. A low, deep, soothing voice. She recalled how delicate he was, how fragile he seemed. Then she saw him lying on the ground, bloody, his precious instrument in pieces. A fresh wave of anger arose.

Her anger morphed into worry - worry if he was all right, if he'd walked away, if he made it home. She imagined him calling to her. Caitlin. Caitlin.

"Caitlin?"

A new voice was outside her door. A boy's voice.

Confused, she snapped out of it.

"It's Sam. Let me in."

She went to her door and leaned her head against it.

"Mom's gone," said the voice on the other side. "Went down for cigarettes. Come on, let me in."

She opened the door.

Sam stood there, staring back, concern etched on his face. At 15, he looked older than his age. He'd grown early, to almost six feet, but he hadn't filled out yet, and he was awkward and gangly. With black hair and brown eyes, his coloring was similar to hers. They definitely looked related. She could see the concern on his face. He loved her more than anything.

She let him in, quickly closing the door behind him.

"Sorry," she said. "I just can't deal with her tonight."

"What happened with you two?"

"The usual. She was on me the second I walked in."

"I think she had a hard day," Sam said, trying to make peace between them, as always. "I hope they don't fire her again."

"Who cares? New York, Arizona, Texas...Who cares what's next? Our moving won't ever end."

Sam frowned as he sat on her desk chair, and she immediately felt bad. She sometimes had a harsh tongue, spoke without thinking, and she wished she could take it back.

"How was your first day?" she asked, trying to change the subject.

He shrugged. "OK, I guess." He toed the chair with his foot.

He looked up. "Yours?"

She shrugged. There must have been something in her expression, because he didn't look away. He kept looking at her.

"What happened?"

"Nothing," she said defensively, and turned and walked towards the window.

She could feel him watching her.

"You seem...different."

She paused, wondering if he knew, wondering if her outside appearance showed any changes. She swallowed.

"How?"

Silence.

"I don't know," he finally answered.

She stared out the window, watching aimlessly as a man outside the corner bodega slipped a buyer a dime bag.

"I hate this new place," he said.

She turned and faced him.

"So do I."

"I was even thinking about..." he lowered his head, "...taking off."

"What do you mean?"

He shrugged.

She looked at him. He seemed really depressed.

"Where?" she asked.

"Maybe...track down Dad."

"How? We have no idea where he is."

"I could try. I could find him."

"How?"

"I don't know.... But I could try."

"Sam. He could be dead for all we know."

"Don't say that!" he yelled, and his face turned bright red.

"Sorry," she said.

He calmed back down.

"But did you ever consider that, even if we found him, he may not even want to see us? After all, he left. And he's never tried to get in touch."

"Maybe cause Mom won't let him."

"Or maybe cause he just doesn't like us."

Sam's frown deepened as he toed the floor again. "I looked him up on Facebook."

Caitlin's eyes opened wide in surprise.

"You found him?"

"I'm not sure. There were 4 people with his name. 2 of them were private and had no picture. I sent them both a message."

"And?"

Sam shook his head.

"I haven't heard anything back."

"Dad would not be on Facebook."

"You don't know that," he answered, once again defensive.

Caitlin sighed and walked over to her bed and lay down. She stared up at the yellowing ceiling, paint peeling, and wondered how they all had reached this point. There were towns they'd been happy in, even times when their Mom seemed almost happy. Like when she was dating that guy. Happy enough, at least, to leave Caitlin alone.

There were towns, like the last one, where she and Sam both made a few good friends, where it seemed like they might actually stay - at least long enough to graduate in one place. And then it all seemed to turn so fast. Packing again. Saying goodbyes. Was it too much to ask for a normal childhood?

"I could move back to Oakville," Sam said suddenly, interrupting her thoughts. Their last town. It was uncanny how he always knew exactly what she was thinking. "I could stay with friends."

The day was getting to her. It was just too much. She wasn't thinking clearly, and in her frustration, what she was hearing was that Sam was getting ready to abandon her, too, that he didn't really care about her anymore.

"Then go!" she suddenly snapped, without meaning to. It was as if someone else had said it. She heard the harshness in her own voice, and immediately regretted it.

Why did she just have to blurt things out like that? Why couldn't she control herself?

If she'd been in a better mood, if she'd been calmer and hadn't had so much thrown at her at once, she wouldn't have said it. Or she would have been nicer. She would have said something like, I know what you're trying to say is that you'd never leave this place, no matter how bad it got, because you wouldn't leave me alone to deal with all this. And I love you for it. And I'd never abandon you either. In this messed up childhood of ours, at least we have each other. Instead, her mood had gotten the worst of her. Instead, she acted selfish, and snapped.

She sat up and could see the hurt etched on his face. She wanted to take it back, to say she was sorry, but she was just too overwhelmed. Somehow, she couldn't get herself to open her mouth.

In the silence, Sam slowly stood up from her desk chair and exited the room, gently closing the door behind him.

Idiot, she thought. You're such an idiot. Why do you have to treat him the same way Mom treats you?

She lay back down, staring at the ceiling. She realized that there was another reason she snapped. He'd interrupted her thoughts, and he'd done so just at a moment when they were turning for the worse. A dark thought had crossed her mind, and he'd cut her off before she'd had a chance to resolve it.

Her Mom 's ex-boyfriend. Three towns ago. It had been the one time her Mom had actually seemed happy. Frank. 50. Short, beefy, balding. Thick as a log. Smelled like cheap cologne. She had been 16.

She had been standing in the tiny laundry room, folding her clothes, when Frank appeared at the door. He was such a creep, always staring at her. He reached down and picked up a pair of her underwear, and she could feel her cheeks flush in embarrassment and anger. He held them up and grinned.

"Dropped these," he said, grinning. She'd snatched them out of his hands.

"What do you want?" she'd snapped back.

"Is that any way to talk to your new step-dad?"

He took a half step closer.

"You're not my step-dad."

"But I will be - soon."

She tried to go back to folding her clothes, but he took another step closer. Too close. Her heart pounded in her chest.

"I think it's time we got to know each other a little bit better," he'd said, removing his belt. "Don't you?"

Horrified, she tried to squeeze past him and out the door in the small room, but as she did, he blocked her way, and roughly grabbed her and slammed her back against the wall.

That's when it happened.

A rage had flooded through her. A rage unlike anything she'd ever experienced. She felt her body heating up, on fire, from her toes to her scalp. As he approached her, she jumped straight up and kicked him, planting both feet squarely on his chest.

Despite being a third of his size, he flew backwards through the door, cracking the wood off its hinges, and kept going, ten feet into the next room. It was as if a cannon had blasted him through the house.

Caitlin had stood there, trembling. She had never been a violent person, had never so much as punched someone. Moreover, she was not that big, or strong. How had she known had to kick him like that? How had she even had the strength to do it? She had never seen anyone - much less a grown man - go flying through the air, or shatter a door. Where had her strength come from?

She had walked over to him, and stood over him.

He was knocked out cold, flat on his back. She wondered if she'd killed him. But at that moment, the rage still filling her, she didn't really care. She was more worried about herself, about who - or what - she really was.

She never saw Frank again. He broke up with her Mom the next day, and never came back. Her Mom had suspected something happened between the two of them, but she never said a word. She did, though, blame Caitlin for the breakup, for ruining the one happy time in her life. And she hadn't stopped blaming her since.

Caitlin looked back up at her peeling ceiling, heart pounding all over again. She thought of today's rage, and wondered if the two episodes were connected. She had always assumed that Frank had just been a crazy, isolated incident, some weird burst of strength. But now she wondered if it was something more. Was there some kind of power inside of her? Was she some kind of freak?

Who was she?