Chapter one: Brother

"A sibling may be the keeper of one's identity, the only person with the keys to one's unfettered, more fundamental self." -Marian Sandmaier

The house smelled like coffee, but not because she was making any. Truth is she hated coffee, but she loved the smell. She had wax warmers all over the house, most with some coffee scent or another. Her preferred morning beverage was a smoothie, usually strawberry, always fruit. The fresh morning wind blew through her open window and the curtains. She moved to close it, wrapping her bright red scarf around her neck and pulling her black, double breasted coat tighter around her with a confident smile at herself.

"Jack, baby, come wish me luck."

She heard the even skittering of feet as her jack russell terrier came into the room and jumped to her bed. She looked over and chuckled, running a finger and scratching under his chin.

"I know you miss Charlie. Don't worry. I'll make sure he comes over soon."

She took a last glance at herself, the red scarf, white, tucked in ruffled blouse, black pencil skirt, coat, pantyhose, and black pumps. No make up aside from a pearl Softlips chapstick that made her lips tingle. A bit cliché, but nice and presentable.

"Well," she said. "Here we go."

Elisabeth drove, tapping her fingers on the wheel and humming an old song- an old Frank Sinatra song she and her brother used to dance to. Today was to be her first day working with her big brother, barely bigger. Only by five minutes. But he never let her forget it, taking care of her as his responsibility.

She saw him as soon as she stepped off the elevator at his desk in what he always called the bullpen. He was standing and not quite pacing, but she could tell he was waiting for her.

"Charlie?"

He looked to her and smiled, rushing to the stairs to lift her away from them and set her on her feet. "Beetle. Missed you."

"You saw me a month ago and now you'll see me everyday. You'll tire of me soon enough."

He hugged her tightly and pulled her towards a desk right next to his. "How was the drive?"

"Fun! I have pictures."

"I still wish you would have let me get you a flight."

She smiled and stole his chair. "Ugh, Charlie, I've watched Final Destination too many times. Besides, it was fun. Jack misses you."

Her twin grimaced. "Yeah, I'm sure he does. That's why he growls at me every time I enter the house. Speaking of, do you like the house?"

"Oh gosh, yes! You are a life saver. It fits all my parameters."

"How do you like the house warming gifts?"

She smiled. She'd missed him. They'd always been close. They read together when their mother's illness became too much for her to. Spencer took his responsibility as a big brother very seriously. Their biggest fight had been her wanting to join the BAU with him because he was afraid of her being hurt.

"Well, the CD I loved, but the coffee maker? Really?"

"It's for when I come over."

"That better be a lot. I missed you."

He smiled awkwardly. "Well, now you'll see me everyday. Your desk is right there." Across from his.

Elisabeth smirked with a gleam he was familiar with and she rolled in his chair over to her desk and passed him the chair meant to be hers. "Here."

"You're going to steal my chair? You realize they're exactly the same."

"No they're not," she contradicted. "This one was yours, which will make it more satisfying for me to sit in."

They stared at each other for a moment and he grabbed the back of her chair, trying to pull it away from under her. "Alright, give it back."

"No! It's mine. You can't have it."

"Tess, you have your own."

"But-"

"Whoa, whoa." She looked up in a moment of pause that they were at work and it was her first day and this was probably not appropriate. This distraction caused her to be thrown out of the stolen chair and onto her knees in front of possibly one of the most good looking men she'd ever seen. Immediately Spencer was at her side and trying to help her up, but her eyes never left those of the tall, muscular man that couldn't be anyone but Derek Morgan.

"Are you okay, Beetle?"

"I-I'm okay." She glanced out of the corner of her eye and saw Spencer still staring concernedly. "Really, Charlie. I'm fine, bu-ut you know what would make me better?"

"You are not getting the chair."

Derek cleared his throat to steal Spencer's attention and her brother straightened and cleared his throat. "Uh, Morgan, this is my sister, Elisabeth Reid. She's starting with the BAU today."

"She a genius too?" The man joked with a wonderful laugh.

"Technically speaking on the scale of intelligence quotient, she's what is considered 'high genius' with an IQ of 167, where my 187 is in the 'highest genius' portion of the scale."

"Charlie, he wasn't being serious."

Spencer looked down to her. "Don't call me that at work."

"Charlie?" Derek asked.

She liked his voice, rich. "It's his middle name."

He held his hand out, a strong hand, for her to shake. "Derek Morgan."

She took it and shook it slowly. He had soft hands. "Tessa."

"It's nice to meet you."

"Likewise."

They weren't shaking hands anymore, but their hands were still joined until they both simultaneously looked down at them and each pulled away. She frowned down at her hand, which still felt warm, and looked back to see him doing the same thing to his own.

"Well," Spencer said. "We should probably introduce you to the rest of the team."

"Right. It was nice to meet you... Derek."

"Tessa."

"What did you think?" He asked late that night, drinking that disgusting beverage with a wonderful aroma.

"I liked it. Is it bad to say I'm excited for our first case?"

"Not bad, but maybe it's just the perspective."

She sighed contently and leaned her head back on the couch. They were both sitting on the floor leaning against the furniture. She was drinking hot chocolate with a dollop of whipped cream, and he a mug of coffee with an inordinate amount of sugar and a spoon of ice cream

"How was mom doing when you saw her last?" He asked in a whisper like he was afraid to get the words out and hear them.

Elisabeth set her cup down very carefully and pet the top of Jack's head, who was laying partially in her lap. "She was fine, I suppose. She stared out of the window like I wasn't even there. I brought her a book, Arthur Conan Doyle like she used to read us, and read a few chapters- but she was just zoned."

He nodded to himself. "Do you ever wonder if we did the right thing? I mean, schizophrenia is a lifelong illness. She needed somewhere that could care for her."

" Charlie, of course we did the right thing. I mean, it was the only thing to do. She's better there with people who know how to take care of her than with us or to be left to let herself go in our absence. We have to live our lives. Isn't that all she ever wanted for us?"

"You're right." He pulled her closer to wrap his arm around her. She leaned her head against his shoulder. Then their phones both dinged with a mass text and she felt a smile spread slowly across her face.

Her first case.

"It snowed last year too: I made a snowman and my brother knocked it down and I knocked my brother down and then we had tea." –Dylan Thomas

A/N: Soooo, written at the request of HannahV123. It will be a bit of a slow burn with a romance between Derek and Tessa, but it might start around the end of the first season beginning of second. I hope the names aren't too confusing. Let me break it down.

My OC's name is Elisabeth, but she prefers to be called Tess or Tessa. Spencer calls her Beetle. She calls Spencer Charlie. Both are the only ones that call each other that. Their mom calls Spencer Crash and Tessa Lily. Derek may or may not come up with his own name for her and I am open to suggestions on that. Hope it doesn't get too complicated or confusing. Also, next chapter I think I'll just be referring to her as Tessa. Let me know what you think in the comment section below. Love always, Skye.