"Okay so let's break down what we know so far," Hotch commanded.

"We know that the Unsub has a degree of instrumental aggression because he's being rewarded with payment for delivery each and every time he delivers a 'shipment'. Chances are the victims did nothing to provoke the Unsub into choosing them - that we know of, and they definitely weren't a matter of convenience, given what we discovered about the birthdays," Emily began.

"When we look at the victimology there's no links, no DNA or detectable signature left at the abduction sites. No connection to each other except for the two hair colours and relative birth date." With the tip of his pen, Derek tapped out a light rhythm to his words onto the pad of paper in front of him. Throwing down his pen in frustration, he got up from his seat and stood beside Reid in front of the board, his fingers now laced together at the back of his neck. They were missing something. He was missing something. The problem was there was a difference between knowing something was missing and knowing what that something was. And right now, he had no clue. With his gut churning in anxiety, Derek continued to stare at the pictures as if by doing so, he could will the answers to suddenly appear. "So how the hell is he finding them?"

"I need a map." Reid said suddenly and he turned away to pull over another empty board. J.J. quietly pinned an open map to the new board, already understanding where he was going with his request. Before he could ask, she started calling out the location addresses of the abduction sites while he began marking them on the map one by one. Then he started numbering them based on abduction dates. Then he picked up a different coloured marker. "I also need their home and work addresses."

Before he was done, the team could already see a pattern emerging. It began with the second victim, Siobhan Kelly and continued right up to the last abduction victim, Bethany Kraft. At the centre of the pattern was the single dot of the first victim, Christina Marx, who to their shock, worked in their building on another floor.

"Looks like we just found a place to start. She wasn't just the first victim, but also the oldest right?" inquired Rossi.

"Yes she just turned 38 just before she disappeared," answered J.J.

"That's kind of old for this type of abduction isn't it?" questioned Emily.

"Depends on what she's being sold for. For sexual purposes or slavery, it wouldn't really matter as long as she could keep up with the physical demands. From the initial police reports and from what little we can see in her photo, at the time of her abduction she seemed to be both healthy and fit. Looks wise, she could have easily passed for at least five years younger," replied Rossi. "When the analyst arrives, we'll run her and see what pops. My gut tells me she's the key."

"Healthy and fit..." Derek muttered as he stared at Christina's photo. Recognition suddenly dawned in his eyes. "Wait, wait, wait, I know her. She signed up for a bunch of my self-defense classes a couple of years ago. It didn't click until J.J. said she was working here and you started talking about her being fit. You're right Rossi, I would have never pegged her for late 30's and I'm a pretty good judge of age. And let me tell you, although slightly skittish, she was the best in my class and put every guy there to shame. She was both strong and had lighting reflexes. There's no way an ordinary guy would have been able to overpower her."

"Morgan, can you remember anything else about her? Which department she was in, maybe how long she was working for the FBI?" asked Hotch.

"Not really Hotch, it was a couple of years ago and I've taught a lot of classes since then. I rarely strike up any conversations about more then the class itself, unless they approach me after class with specific questions." Derek rubbed at the back of his neck as he strained to recall more information. "She was quiet, kept to herself, and was always gone the second class was over. The only reason I even remember her is because I kept wondering why she wasn't teaching classes instead of taking them - she was that good, at least technique wise. All I could come up with was maybe it was a confidence thing. The only other thing I remember was that she didn't wear a wedding band, but had a tan line on her ring finger. At the time, I never questioned it or gave it a second thought because I just assumed she took it off for class, but maybe it was because she was recently separated or divorced. It would definitely go a long way to explaining why she kept taking self-defense classes when she clearly didn't need them. Especially if it was a particularly nasty break up. And it could in turn have something to do with why she's missing now. If she is the key, that's definitely the first person we need to be looking at."

The last of his words were punctuated by a sharp knock on the door. When J.J. swung it open, you could have heard the single beat of a humming bird's wing in the absolute silence. Derek's knees buckled and he was forced to swiftly grab onto the edge of the table or fall to the floor in a trembling heap. In that one explosive moment, he swore he felt his heart falter and come to a complete stop.