Getting inside the mind of a serial killer is one thing. Getting inside the mind of my genius twin brother, however, is a completely different thing. Working at the Behavioral Analysis Unit out of Quantico is everything I had hoped it would be and more-studying behavior, delivering profiles, not to mention kicking tons of criminal ass. With the help of the best team anyone could ask for-and yes, that includes my genius twin brother-we bring down the worst of the worst and get inside the twisted heads of some of the most dangerous and prolific serial killers of our time.

My name is Special Agent Allyson Reid and this is my story.

"...and with this area of low pressure pushing into the area, we could be seeing quite a few more days of rain. Maybe even a snow shower or two as temperatures dip down into the high 20s with the arrival of the weekend."

The reporter on the news channel continued with the evening weather report, but he barely noticed it. He'd barely noticed it since he first came into the house. Sarah had been busy watching television when he arrived. Family Feud had been on. He could tell that she really enjoyed that show. In fact, he had to ring the doorbell several times to tear her away from the set. But once she opened the door, the cheers, claps, and calls of "Survey says!" were lost amid her screams.

The screams had subsided over the last hour, but he doubted she had much energy left anymore. Not after what he had done to her. if she had any brains at all, she would be thanking him. A girl like her, sitting inside on a Friday night, eating junk food and watching game show reruns on television? Who was going to fall for someone like that? Who was going to be able to give her the release he had just given her? Again, and again, and again...

A muffled sob rang out from behind him. He turned around, staring at Sarah through the slits of his mask. He didn't know why he was still wearing it. She wouldn't be able to identify him. Not after he finished with her. Perhaps it was because by keeping it on, she still had hope that he wouldn't kill her. She still had hope that he would eventually leave. And he still had exactly what he wanted from her: control.

"Please," she cried, her voice barely more than a whisper anymore. "Just tell me what you want."

He smiled as he leaned over her on the bed, pushing her matted, dark hair out of her face, her tears and sweat mingling with the blood from the blow he'd given to subdue her. If she had just let him into the house in the first place, he wouldn't have needed to be so forceful. He wouldn't have needed to tie her to the bed. (Actually...that part was all for him.)

"Shh..." he said, placing a finger on her lips, wiping a trickle of blood from the corner of her mouth with his thumb. "Savor this, Sarah. You're never going to have another night like this."

She started crying, turning her head away from him. He disgusted her. She couldn't even look at him anymore. After what he'd done for her. After what he'd given her. She didn't deserve him. She didn't deserve anyone.

"You're never going to have another night like this," he repeated as his hands found her throat. "Never, ever again."

Her sobs cut out as he tightened his grip.

Tak. Tak. Tak.

Allyson Reid groaned and rubbed her aching eyes, willing the letters and numbers on the screen to start looking more like coherent words and less like the jumbled mess that had currently formed in her mind. How long had she been working on this report? One hour? Two hours? Half a day? (A brief glance at the clock revealed it had only been about fifteen minutes, but it definitely felt longer.) Maybe if she just rested her eyes for a few minutes, the time would go faster...

WHUMP!

Allyson hurriedly jerked away as what sounded like a small avalanche came cascading down on her desk. The source of the noise turned out to be a stack of folders, and the culprit-as she had already guessed-was none other than her "rather hilarious" (his words, not hers) coworker, Derek Morgan.

"Damn it, Morgan!" she cussed, straightening herself and lightly smacking the back of her twin brother Spencer's head to make him stop snickering. "You scared me half to death!"

"Well, that's what happens when you get caught snoozing on the job there, Street Fighter," Morgan replied with a grin. "What's got you so tired?"

"None of your business," Allyson replied casually, reaching for her energy drink only to realize, to her immense disappointment, that it was empty.

"Ooh, someone's cranky in the morning," Morgan said.

"You have no idea," Spencer replied, resulting in another smack in the back of his head from his sister.

"So what? You keep her up all night discussing your Star Trek theories, Reid?" Morgan asked as if needing to remind everyone of the fact that the team genius was also a huge nerd.

Allyson rolled her eyes as she got up to grab another can of Monster from the staffroom fridge. "Okay, first off: I'm a Star Wars girl. Everyone knows that. And secondly, like I said, it's none of your business."

"I'd lay off her, man," Reid said as Morgan opened his mouth to argue. "Until she's consumed half of that four-pack she brings to work every morning, she won't tell you much of anything."

Well, he's got a point there, Allyson thought to herself. But even if she had already had her usual two Monsters (damn her brother's eidetic memory for knowing how much of this crap she really drank), she wouldn't tell Morgan the real reason she was so tired. She hadn't even told Spencer that the nightmares were coming back. It had taken so long to convince him last time that they had really stopped. At least she was getting better at not screaming at night as much. The apartment walls were thin and, given the fact that their bedrooms were right next to each other, it didn't take much to wake her brother up.

"All right, keep your secrets," Morgan said, grabbing his stack of files and settling himself into the desk in between the twins. "I know all about those special nights," he added with a wink. Allyson rolled her eyes, but couldn't completely hide a smirk.

The lighthearted banter, however, was short-lived as the door to the Communications Liaison's office opened and Agent Jareau emerged, holding a file and looking distressed in the way only a tricky case could do. She glanced briefly at the three of them before giving a defeated sigh and tucking a long strand of blonde hair behind her ear.

"Bad, JJ?" Allyson asked, even though her face had already answered the question.

"Bad," she replied sadly. "Conference room in two."

Looks like I won't be finishing that report after all, Allyson thought as she, Morgan, and Reid got up and headed towards the conference room. As they neared it, Reid leaned over and half-whispered in her ear, "You aren't having 'special nights' like Morgan suggested, right?"

Allyson nearly choked on her drink as she fought to stifle a laugh. "Even if I was, I doubt I would be telling you that, little brother."

"Okay, again," Reid began in that know-it-all tone of his. "Just because you were born first doesn't mean I'm your 'little brother.' We are technically the same age."

"Well, I'm six minutes older so that means I make the rules and I say it does," Allyson replied.

"Yeah, but I'm seven inches taller than you," Reid interjected (which was true; he'd inherited their mother's height). "So if anyone should be referred to as 'little,' it's definitely you."

Allyson started to retort, but, realizing it wasn't worth it, merely shook her head. "I'm too tired to do this."

"Well, that's a first," came the voice of their superior Jason Gideon as he entered the conference room, a newspaper tucked under one arm and his reading glasses perched on the end of his nose. "You're never too tired to give your brother crap."

"Guess I'm full of surprises," Allyson said with a smile as JJ began passing around case files."

"All right, everyone, settle down," came the commanding tone of their unit chief SSA Aaron Hotchner (more commonly referred to as "Hotch" by the members of the team). "JJ, whenever you're ready."

Despite the fact that she dearly loved her job (and not just because it gave her a chance to give her brother shit every day), Allyson always found herself silently dreading these board meetings. Granted, they had gotten better over the years (once the demons in her past weren't quite so prevalent in her mind), but every once in a while, a case would be presented to them that brought unpleasant images back into her mind. (Almost like her nightmares last night had been telling her something.)

It was this tragic back story that ultimately pushed Allyson into wanting to join the BAU in the first place. She'd been no stranger to picking fights with the bad guys ever since she was a little girl. And she owed all of that to her brother. With an IQ of 187, an eidetic memory, and the ability to comprehend 20,000 words a minute, Spencer was a certified genius (even though he claimed that intelligence was not something that could be accurately measured). But considering the fact that her twin brother had graduated high school before she even started it, Allyson didn't really know what else to call him.

Unfortunately, most of the kids in the Las Vegas public school department didn't see it quite the same way. And a lot of the 10th graders weren't too keen about having a 12-year-old in their class (who was noticeably smarter than them), and they weren't too shy about beating up the wimpy nerd any chance they got.

Sadly for them, they didn't know about Allyson.

Sick and tired of watching bullies take advantage of her brother, Allyson set about learning several styles of martial arts, as well as basic self-defense. By the time she was in junior high, she was practically untouchable. And after Spencer came home from school bruised, bloodied, and crying one too many times, forcing her to put three members of the varsity football team in the hospital, they thought twice about messing with either of them from then on.

Despite their young ages, the Reid twins made it to the FBI fairly quickly. What Spencer lacked in physicality, he more than made up for in brains-hell, the boy had three PhD's before he was even old enough to drink!-and while she wasn't at quite the level of genius as her brother, Allyson's combat skills rivaled almost everyone in their division. (Morgan still refused to admit he didn't just "let her beat him" the last few times they sparred.) When the two of them put their heads together, they were unstoppable.

As was tradition in the BAU, members of the team typically went by their surnames-Agent Jennifer Jareau being the exception as she preferred to abbreviate her alliterative name into merely "JJ". However, because Spencer had started about six months before Allyson and had already been coined "Reid," Allyson merely went by a shortened version of her first name (because everyone agreed that saying "Reid" and "Other Reid" was just too confusion). But she didn't mind. With the amount of books her brother had finished in his short lifetime, "Reid" seemed like a much more appropriate nickname for him anyway.

The folder on the table in front of Allyson was, as usual, filled with images that made her heart heavy. This particular case file involved pictures of two women, each laid out on the side of a dirt road, wrapped in a blanket and dressed in nothing but their undergarments. Dark bruising around their wrists, ankles, and necks indicated that they had been restrained and strangled. Their attire, Allyson sadly realized, most likely meant they had been assaulted as well.

Why today of all days?

"Sarah Lawrence, age 23, and Danielle Markinson, age 26," JJ began, projecting photos of the two victims on the screen behind her. "Both women were discovered in ditches off the side of the road. Sarah was discovered early Saturday morning, Danielle about two day before. Both were beaten and sexually assaulted."

Even though that much was obvious, it still was never easy to hear. "Were they covered like that?" Allyson asked, gesturing to the blankets.

"Yes," JJ replied. "Their bodies were wrapped up in the blanket, but our unsub left their heads exposed."

"So he wanted the bodies to be found?" Morgan asked.

"It's possible," Hotch said.

"Covering them could be a sign of remorse," Gideon added.

He wasn't very remorseful when he raped them, Allyson thought savagely.

"The bruising on their wrists suggests they were restrained," Reid said.

"And on their neck," Morgan began. "That means-"

"He strangled them," Allyson finished, noting how her voice temporarily broke on that statement. She really hoped nobody else noticed.

"Yes, both women were strangled to death," JJ said. "But that's not all. These two women aren't our unsub's only victims."

"Are there more bodies out there?" Morgan asked.

"Not exactly," JJ replied. "There aren't any bodies because the other victims aren't dead." When everyone continued to look confused, she elaborated. "After details got out about Sarah Lawrence's death, other girls started to come forward, all claiming to have been raped by the same man. Their stories go as far back as six months."

"Is there proof to back it all up?" Hotch asked.

"Those who agreed to rape kits all tested positive for assault," JJ replied. "And the more recent victims had bruising that matched Sarah and Danielle."

"So something changed that made him go from assault to murder," Morgan said. "A stressor in his life."

"The assault alone wasn't providing him satisfaction," Gideon replied, sounding (as usual) like he was reading the unsub's mind. "Killing them provided him with the release he was lacking."

"Were any of the previous victims able to give a physical description?" Reid asked. Allyson saw him glance towards her, but she pretended at first like she didn't notice. She knew what he wanted to ask her, but now was not the time.

JJ sadly shook her head. "A lot of them have suppressed the memories of that night. Those that do remember say that he kept his face hidden."

"Well, two bodies in two days means he's escalating fast," Hotch said. "We need to act fast before we risk another body. Wheels up in thirty."

There was a scraping of chairs as everyone closed their case files and headed for the door to grab their things and get any last minute tasks taken care of before they headed to the jet. Allyson took a bit longer, waiting until most of the team had left before closing her own file. Okay, deep breaths, Ally. You've done cases like this before. It's going to be fine.

She got to her feet and barely resisted the urge to scream as she noticed a tall figure standing behind her.

"Damn it, Spencer! You scared me!"

"I'm sorry," Reid responded. "I didn't expect you to be so jumpy."

"I'm not jumpy," Allyson retorted. "I just didn't know you would be standing there."

Reid fell silent as if suddenly second-guessing what he had wanted to talk about. Allyson decided to put his mind at ease.

"You can relax, okay? I'm fine." She hoped that by saying the words out loud, her mind might actually start to believe them. "We've handled assault cases like this before."

"I know," Reid said. "But I also know this time of year is difficult for you. And I know you haven't been sleeping well lately."

"Well, neither have you," Allyson replied. "You think I don't notice the living room light on at 3:30 in the morning?"

"I like reading at night. It's easier to focus."

"Mhmm...sure," Allyson said, smirking slightly.

Reid hesitated for a minute. "Have you talked to Hotch-"

"No," Allyson replied hurriedly. "And until it starts to affect my work, he doesn't need to know."

"It might be good to tell him."

Allyson took a deep breath. As much as she wanted to be mad, she knew her brother was only looking out for her (he had this annoying habit of doing that). "Look, I understand your concern and I appreciate it," she began. "But I wouldn't have taken this job if I couldn't handle it."

"I know," Reid said again. "I just don't want you to try to handle everything by yourself."

Allyson groaned. "Why do you have to do that?"

Reid frowned. "Do what?"

"Care like that," Allyson replied. "It's ruining my image of being the troubled agent with the dark and mysterious past."

Reid smirked. "Well, you're my twin sister so that image is already way out the window."