Disclaimer: I do not own any of these characters in any way. Simply borrowing them for my own pleasure.

I did not use a beta reader, so all mistakes are my own.

Characters' thoughts are in italics

Chapter 6 - Alters and Hosts

The four of them had driven back to 1 PP. The rest of the day was spent going over their individual notes, typing up reports and laying out plans for the continued investigation.

Hotch and Alex had finally given up around 10 pm and gone off, separately, to get some sleep.

Bobby and Spenser, who found they were kindred spirits in the world of insomnia, were sitting in front of two large evidence boards, staring at 8 of the letters Jo had sent Alex. They spanned a 9 month time frame, with the last being sent 2 days before she bite off most of her tongue. Both felt there had to be something in them, but what?

As he stared at the letters, his mind drifted to Declan. Bobby had seen something in Declan's face during the interview at Riker's that morning that he had never seen before, not even on the day of his confession. Dec had seemed insane that day, but the person he saw in the prison had a core of steel that he had never imagined Dec possessed. Almost like seeing someone else. "Like he was someone else," Bobby said out loud, almost too low for Spencer to hear it, but not quite.

"You saw that too?" Spencer asked.

Bobby nodded. "It was his face. It's like a shadow passed over it."

"I don't know him like you do," Spencer said, "but I felt like I was talking to two people. I..." he paused.

Bobby looked over at the young man and saw the pain on his face. "What is it, Spencer?"

"I've experienced this before." Spencer took a deep breath and looked away before he continued. "I, umm, was held captive...for several days...by a serial killer named Tobias Hankel, who had Dissociative Identity Disorder. He floated in and out of himself and his 2 'alters'. I would almost swear that was what Gage was doing, though not as cleanly."

Bobby stifled the urge to tousle the younger man's hair, like he was prone to do when dealing with a "lost" young man. He knew Spencer was not one of this lost boys, he was an expectationally bright FBI agent, who just happened to look like a teenager. Instead he put a large hand on Spencer's shoulder and gave it a gentle squeeze. "I'm sorry you had to go through that."

Spencer looked up at him for a moment and felt that he had been right to trust Bobby with this painful and personal revelation. He nodded his thanks at Bobby's gesture.

"Multiple personalities, rare, controversial among the psychiatric community," Bobby mused out loud as he continued to stare at the letters and started wondering again about the mistakes he saw. "Do you remember what you said about Jo being a bad typist?"

"Yeah. She skipped spaces where she shouldn't have. Sometimes left off the last letter from some of the words."

"Does it bother you that the errors occur only occasionally, no more than 3 or 4 times per letter? If she was really a bad typist shouldn't the mistakes be more wide spread?"

"It does seem less than random, Bobby. The mistakes also don't appear in the first 7 letters, only the last 8."

"Yeah, and by the dates of the letters that was when Dec visited her the most, according to the visitor's log at Bedford Hills. He told me he had been writing a book about women serial killers. It was published right along that time so he would have needed something else to occupy his time. Maybe Jo was the occupation." He slid off the table and looked at the letters again intently. He pulled them off the board and fanned them across the table, arranging them chronologically by the date written. Suddenly he grabbed a highlighter and began marking the sentences in the letters that had the skipped spaces. Then he went back and underlined the skipped letters themselves.

I miss eating corn on the c ob.

Has the weather turned c ool outside?

Watched that big basketball player, Sha q, on TV yesterday.

Can you settle a bet, are all ca rp goldfish?

They brought a li v bird show here.

I been reading a lot ofbooks by James Patterson lately.

They finally turned the heat of f here.

Did your mother wear an ap ron?

At services today they talked about the rod and the staf f.

Do you think Prince Charles will ever be kin g.

I ha v lot of free time, but too much time for thinking.

We actually got a bana na today, but I hate them.

Let me tel l you about my favorite new book.

Dad spent too much time in his la b.

Not sure which h one to start with.

Now I wish I was a better gard ner, might be able to see the sun more.

I miss hearing dogs b ark.

Funny thin g to say I guess.

Lots o f new staff here now.

So many people beggin g for cigarettes everyday.

Can you imagine using a ca b to visit a prison?

De c is coming for a visit soon.

Yo u are a good person Alex.

I ha v made a new friend.

We saw the Wizard of O z at movie night.

As soon as Spenser realized what Bobby was doing, he began writing down the underlined letters, exactly in the order they appeared in Jo's letters.

ob ool q rp v f f ron f g v na l b h ark g f g b c u v z

"Some of the letters are grouped together after the extra space. Some of the words had dropped endings, maybe because she couldn't find words that ended in those consonants?" Spencer spoke out loud as his brain ran the letters through its own code recognition software. "Bobby, how intelligent is Jo?"

"Very. But if I know Jo she would make it something I would be able to figure out. She knows me pretty well."

Did you two ever use a code for anything?

No. It was Declan I spent the most time time with. Jo was always there, but...

Spencer began to smile. He had it. "Were you a Boy Scout, Bobby?"

"Actually, I was, for a while." He looked at Spenser quizzically, before turning his attention to the letters Spencer had written. "It got me out of the house. Why do you wanna..," then suddenly he saw it too. He smiled back at Spencer, grabbed his cell and pressed a button. "You call yours, I'll call mine."

Less than an hour later all the four of them were looking at the message Jo had woven into her last eight letters.

Spencer pointed to the line of letters he had transferred to the large white wipe off board and began to explain. "Jo used a code commonly taught to Boy Scouts. Its called the Half-Reversed Alphabet code. It's basic, but not immediately apparent when used the way she did, which was to weave the coded letters into ordinary words with the coded letters separated by a space which at first glance just looked like bad typing skills." The young man's voice was so enthusiastic, that Alex found herself smiling slightly and thinking about how her partner used to look like that when he had a solution by its tail. "You write out the alphabet A to M and then under that write out N to Z, like this" He wrote it out for them on the white board:

a b c d e f g h i j k l m

n o p q r s t u v w x y z

"You use the same alphabet for coding and decoding. A stands for N and N stands for A. B stands for O and O stands for B and so on. If we apply that cipher, here is what we get - "

ob ool q rp v f f ron f g v na l b h ark g f g b c u v z =

bo bby d ec i s s eba s t i an y o u nex t s t o p h i m

If we then group the letters into logical word patterns, you end up with this:

Bobby Dec Is Sebastian You Next Stop Him.

Alex spoke up. "Spencer, are you sure about your code?."

"I saw it too, Alex. Maybe not as fast," Bobby answered, shooting a quick grin at the young genius, "but I agree with his conclusion." He was actually thrilled to be sharing the discovery with someone who understood what it was like to make the intellectual leap, though admittedly Spencer was faster.

"What do you two think she means by 'Dec is Sebastian'?" Hotch asked.

"It's Tobias all over again, Aaron."

"Reid, DID is rare. Even with the kinds of cases we work." Hotch was looking at Spencer carefully. The Tobias case had nearly destroyed the young man. That he would willingly discuss it, even this little bit, either meant Spenser was sure he was right or he was more messed up about it then Hotch thought he was.

Bobby turned to Alex. "DID, Dissociative Identity Disorder also still sometimes known as Multiple Personality Disorder."

"What are you saying? Gage has multiple personalities. Like Sybil? Please. You two need a nap." She gestured at her partner and the younger agent. "This is what happens Hotch, when playtime for the kiddies is not well monitored. I can't believe they interrupted my beauty sleep for this." She started to get out of her chair.

"Eames, I saw it. It was right there on his face, in his demeanor." He didn't turn to her, didn't even try to make eye contact, but she heard it in his voice as clear as if he said the words out loud – Trust Me.

She sat back down, the look on her face softening. "I know you want an explanation for this that somehow makes your faith in your mentor well founded. I get that. If Gage..." she was going to say 'was sick' but that went without saying. Multiple personalities or not, Gage would always be sick in her book. "Jo is probably just trying to screw with me, and you. She had a lot of times on her hands, you know."

Bobby looked at her for a moment before speaking. "She could have 'messed' with us in far more straight forward ways. Alex, a diagnosis of DID would explain the differing results on his three EEG's."

"I read that research," Spencer confirmed. "If the Alter is the one being tested and that personality is strong enough, even the brain waves of the Host could be altered, depending on which one was in control."

Alex started repeatedly tapping her index and middle fingers in a two tap pattern, against the left side of her shirt, right below her collarbone.

"Uh, Alex. What are you doing?' Spencer queried.

"I'm trying to activate my Communicator Pin. We are on the Starship Enterprise right, Data? I need to beam out of here." She snorted. "Alter and Host. Could you please speak English for those of us who have a life and don't live in a medical journal."

"I didn't know you liked Star Trek, Eames." Bobby added, amusement written all over his face.

She ignored him.

"Alter refers to...Dr. Reid began.

"Spencer," Alex said. "I get it. Just making a point is all. Gentleman, I am usually willing to go along with any ride, as my partner will tell you, but this one may be too strange, even for me."