Disclaimer: CBS owns both Numb3rs and Navy NCIS, including, but not limited to, characters, plot, and Charlie's hair.

Author's Note: This is my response to a challenge given by D. Lerious. Thanks for the idea! It is a crossover between Navy NCIS and Numb3rs. I will be switching between viewpoints, but hopefully I keep it clear from whom the section of the chapter is coming from. To add to the clarity, the periods in a row above a section show that the next section is to be told from an NCIS perspective, and the row of numbers indicate that the next section is to be told from a Numb3rs perspective. I hope you enjoy, and as always, read and review!

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"Gibbs. A word please."

Special Agent Leroy Jethro Gibbs looked up from his desk to find the director standing over it. "Now, Jen? I've got work to do on this case-" he whined before she cut him off.

"That's what I'm here to talk about, Jethro." She gave him the stare that he knew not to disobey. They walked off to her office before either one of them spoke again. When she spoke, Shepard was frank.

"You aren't getting anywhere on this case, Agent Gibbs."

"Not yet. But my team is working on it," Gibbs replied.

"And how long are you planning to let them 'work on it'? Like I said, you aren't getting anywhere on this case, and I preferably do not want to get more data with these numbers. Therefore, I am ordering your team to hire someone that can find a pattern to these numbers." Shepard looked down to her own work, obviously trying to end the conversation. However, Gibbs continued to watch her, a smirk trying to form on his face.

"And how long do I have to find this person? Who would drop all their work to come help us on patterns?"

"That is up to your team to figure out. However, I would check the Los Angeles area. I've heard good things about them. As for how long you have to find this person, I want him or her hired within the next twenty-four hours, here in D.C. in thirty-six," Director Shepard replied, not looking up. When Gibbs refused to leave in the next minute, she finally met his eyes. "Do you have any more questions, Jethro?"

"No. Of course not, Director."

"Good. Then you are dismissed."

… … … … … … … … … … … …

Special Agent McGee stared at the screen, his head resting on his hand, as he watched the numbers fill the screen. By now, though, they were blurred, and he wasn't really paying attention to them anymore.

"McGee! What are you doing?" Gibb's voice rang out through the room.

McGee sat up straight in response. "I was…uh…I was running through the numbers again, Boss. Seeing if I could find the pattern between them."

"What, for the fifty-seventh time?" Without waiting for a response, he continued. "Did you find anything new?"

"No, Boss. I haven't." His face started to redden. But what else was he supposed to do? Tony and Ziva were both off, talking to the families of the victims, and he had nothing else to do.

"Not the answer I wanted to hear, McGee, but it doesn't matter anyway. Stop doing that for now, and try to find someone that can come out and possibly find a pattern behind these murders," Gibbs ordered before he headed off to the elevator.

"Who am I supposed to find, Boss? A specific consultant?"

"Find a mathematician for all I care. Just follow the director's orders! I'm heading out for coffee." McGee followed him with his eyes until the doors of the elevator closed in front of Gibbs. Biting his lip, and not knowing how he would do it, he set off to work.

Half an hour later, Tony and Ziva returned, bickering about something or other, like they usually were. They both greeted him shortly before continuing with their argument, but he couldn't remember if he responded or not. He thought he found the perfect person, but who knew how well this guy actually did on these kinds of cases. For some reason, he had to continue looking on his background.

Gibbs returned not much longer after Tony and Ziva did, muttering about long lines at the local coffee house. Seeing McGee concentrate so much on the computer, he asked, "Did you find anyone yet?"

"Uh…yes, I have, Boss. I'm just finishing up his background."

"Well, pull him up, let's get a look at his file," Gibbs responded, sitting at his desk.

Putting the profile up, McGee began to talk about the consultant he had been looking at.

"Doctor Charles Eppes. Thirty, lives in Pasadena, California. He is a professor at a small college there, Cal Sci, teaching mathematics. Also, for about a year now, he has been consulting for the FBI office in L.A., using math to find patterns of suspects. He also has clearance with the NSA," he recited, giving as much information as he had.

"Sounds good, Probie, but what do we need to see the Doctor for?" Tony asked.

"To fulfill the director's orders, DiNozzo," Gibbs shot back. "He sounds as good as anyone, McGee. Call him up, see if he'll come out to D.C."

"Got it, Boss."

"And did you not hear the sarcastic tone I had when I said, 'Find a mathematician'?"

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"Eppes."

Special Agent Don Eppes answered his cell phone, expecting the call from Charlie. They were supposed to be surprising their father with a nice dinner, since neither one had been around much lately. Charlie was supposed to be pulling a few strings with an old student of his to get a nice table, and he was supposed to call when he was done. So he was surprised when an unknown voice responded.

"Doctor Eppes, this is Special Agent Tony DiNozzo of NCIS. We are sorry to bother you like this, but we would like to hire you as a consultant on one of our cases."

"Hang on, this isn't Doctor Eppes." Don felt a little weird referring to his brother as "Doctor Eppes", but he could live with professional courtesy. He felt even weirder at the fact that this Tony DiNozzo called his cell phone asking for Charlie.

"It isn't? Oh…umm…could you hang on a second?" The voices on the other end of the phone became muffled. Don couldn't help but feel that Tony was quite rude, not even asking if he was in fact "Doctor Eppes" before launching into his little speech. But why would NCIS want to hire Charlie?

… … … … … … … … … … … …

"It isn't? Oh…umm…could you hang on a second?" Special Agent Tony DiNozzo put his hand up to the phone, trying to muffle the confusion that would be sure to start.

"Probie? I thought you said this was the phone for Doctor Eppes?" Tony shouted across they way.

"It is. Or, at least, I thought it was. Hang on…" Tony could see McGee's eyes scan the computer quickly before continuing. "Yeah, it says here that this is the phone number for Agent Eppes. Agent…oh. It's Special Agent Donald Eppes. They must be related."

Tony walked over, phone still in hand, and smacked McGee on the back of the head. "You think, Probie?" he asked.

Gibbs immediately came over, and whacked Tony on the back of his head. "Don't whack him, DiNozzo. Only I get to do that."

"What love we have here," Ziva observed from her corner.

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"Oh. It's Special Agent Donald Eppes. They must be related." Through the muffled sounds, Don could clearly pick that up. After all, he'd been hearing things like that ever since his parents were told that Charlie was a genius. He still heard these things, even though he had distinguished himself from Charlie, but high school was the worst time for that. As the agents at the other end of the line squabbled, Don couldn't help but remember some of the worst words he had ever heard in his life.

High school years were great, for the most part. Yeah, so his nine-year-old brother would be starting high school with him, but he could live with that. "Keep him out of trouble," his parents had said. And although he had to save his younger brother from a few bullies that first year, Don didn't need to worry about Charlie all that much. In fact, he tried to avoid him at all costs.

Freshmen year had come and gone. The two of them had none of the same teachers, so no associations were made there. His brother tried to get his attention in the hallways between classes, but Don ignored him unless something was really bothering him. Charlie would have that hurt look on his face, and it stung to see him with it, but Don grew used to it. One hundred and eighty days of that look did that. Besides, as long as he played some basketball with him in the afternoon, Charlie didn't seem to mind.

Sophomore year ruined that. Suddenly, he had trigonometry, the same teacher that Charlie had the year before. The teacher quickly realized that, and expected Don to be just as good as his brother. The other students found out, and suddenly he was no longer the cool Don Eppes, just the guy with the freak of a brother. Don was determined to change that, and threw himself into his baseball, soon becoming the star of the team.

Graduation was the absolute worst part of the four years. On a day where everything was supposed to be final, everything was supposed to be good, Don's world came crashing down. And although it was only a few seconds, Charlie was a high school graduate and he wasn't. He never got over that.

And now people were asking for Doctor Charles Eppes to help with a case, not the FBI agent himself. A pang of jealousy quickly shot through him, but he was able to get over it quickly. The two of them had grown closer than ever in the past year. Why shouldn't Don be proud of his younger brother?

Agent DiNozzo's voice pulled him out of his thoughts. "This is Agent Donald Eppes then, right?"

"Yes."

"Are you related to Doctor Charles Eppes?"

"Yes. Charlie is my brother." Again, the pang of jealousy shot through him, as he, once again, had to say that they were brothers. I'm over that, though. I'm a separate person now. I'm proud of my younger brother.

"Would you mind giving us some contact information for you brother, Agent Eppes?"

"Actually, I would. Why do you want to talk to Charlie?"

"Well, NCIS is not allowed to talk to anyone that is not working on the case-"

"Not even the FBI?"

Don could hear Agent DiNozzo chuckle. He figured it would take a while to get some answers, so he settled into his chair, and began to mentally set up his interrogation plan.

… … … … … … … … … … … …

Gibbs was staring pointedly at DiNozzo, urging him to hurry up. DiNozzo glanced over at him, and a small chuckle escaped his mouth.

"Well, personally, even I am not at liberty to tell the FBI. However, my supervisor would be happy to answer any of you questions, Agent Eppes." Pulling the phone away from his ear, he motioned to Gibbs to take the phone.

Rolling his eyes, he took the phone. Instantly, he got down to business.

"Listen, Agent Eppes. My team has been working on a case for two weeks. Our killer has been leaving a code for us in numbers, but we have not been able to crack it. We know that Doctor Eppes consults for the NSA and the FBI on these kinds of things, so we want to hire him. Any other questions?" Gibbs didn't hear anything, so he continued. "Now, could I please get Doctor Eppes' contact information?"

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"Any questions?"

Don was too stunned to speak. Would it really be hard for Agent DiNozzo to give him that information? Sometimes he wished he had someone like Agent Gibbs on his team to give him straightforward answers.

"Now, could I please get Doctor Eppes' contact information?"

Don finally got over his shock in time to answer. Somehow, he got the feeling that he did not want to anger this Agent Gibbs.

"Well, his cell phone is currently off. But I will be speaking to him tonight, so I will mention it to him and have him call you."

The two of them exchanged information before Don hung up.