- - - - -

"Hey, Dad? Charlie?" Don shed his coat and threw it over the back of the couch, moving into the dining room, then heading upstairs. He saw shadows moving under Charlie's door, and opened it. Charlie was still in his pajamas, and he and Larry were perusing the pile of equations and graphs strewed across the bed. Charlie looked up when the door opened.

"Hey, Don."

"Hey, buddy, how you feeling?"

Charlie shrugged. "Aren't you supposed to be down at the office?"

"Yeah, I just…well, I guess you and Larry should both hear this." He closed the door and seated himself in a chair next to the bed. "Look uh…I've got some bad news." Larry and Charlie watched him expectantly. "There was a bombing at CalSci this morning."

"What?" Charlie sat up and Larry put both hands over his mouth. "Wha- when? Where was- was anyone hurt? Did anyone-"

"Charlie, Charlie calm down. No one was hurt, the building was empty."

"Which building?" Larry asked.

"The Blaise Pascal lecture hall."

"That-" Charlie sat back, looking stunned. "That was…I was supposed to give a lecture there this morning."

Don watched him. "Yeah, I know."

"Don, if I hadn't…gotten sick, I'd be-"

"Hey, listen the important thing is you weren't there, okay?"

"Why would they bomb an empty lecture hall?"

"I dunno, but we're doing everything we can to figure this out."

Larry kneaded his forehead. "Do you have any leads, or…"

"A few. For now it's looking like organized crime. We've thought for awhile now that two suspected gang leaders we've had in custody were attempting to keep in touch with their gangs. And this makes three bombings with the same basic MO within just a few days of each other. That's the lead we're following right now, anyway." He shrugged, feeling all of a sudden like he'd said too much. "But we're not sure of much yet. Look, we'll let you know when we know more, okay? Charlie?" Charlie just nodded numbly, and Don decided to stick with that. "Okay. Get some rest, all right?"

"Yeah." Don got up, hesitated in the doorway, then disappeared, closing the door behind him. Charlie was silent for awhile, listening to Don's footsteps resound down the stairs. A few minutes later, after an inaudible conversation with their dad (in which, Charlie assumed, the bombing did not come up), he heard the front door close. It was then that Larry spoke.

"I find it ironic that a group of people who provoke chaos are celebrated as members of 'organized crime'."

Charlie just shook his head, mind working furiously. "You know what scares me the most…I seriously doubt they intended to strike on an empty building."

- - - - -

Don threw the stack of papers onto the desk in front of him, drawing the room's attention. "Okay, what we've got so far: We've received the report back from forensics. At this point, they're saying it was domestic."

Colby pulled up a report on the computer. "All the elements of the bomb, as far as they could tell, were either homemade or black market. Either unprofessional work or very convincingly unprofessional professional work."

Don leaned over to look at the report. "Have we cross-referenced the full analysis with the other bombings?"

"Yeah," Megan said, pulling out a brown folder. "Both at the grocery store bombing and that Cajun restaurant. Same basic set-up, same equipment. I think it's safe to say if it isn't the same person, it's the same gang. Always providing it's not a copycat. Man." She gave them an exasperated expression. "Don't you just wish criminals would come up with their own ideas?"

"Guys," Don said as Megan handed him the folder. "We're going to run with the organized crime theory. I want a profile on both of those gang leaders ASAP." The room started moving, and Don had to yell to finish. "If one of these guys is keeping his boys moving, it's possible we can use him to track the gang down, so let's get on it!"

Megan wheeled her chair away from the table, turning to face Don. "Did you tell Charlie?"

Don sighed. "I don't think I've ever been so relieved that he's in bed with a temperature of one-hundred and one."

Megan frowned, stacking up the papers. "You know I just don't get it. When a gang leader gets incarcerated, his buddies usually either go underground till he's out or someone just takes over. I mean, have you ever heard of this much loyalty among reprobates?"

"If they honestly believe that he's the one guy who can really get things done, then yeah." He shook his head. "I just don't get the targets. A grocery store, a restaurant and now a lecture hall at CalSci."

"It could be completely random."

"If you were going to risk sending messages to your slum buddies, would you really give orders for random attacks?"

"Probably not. A psych report on the boys inside would be nice, though." Megan handed him a folder marked Crime Scene (case 441992835). "Here's the photos and police report on the CalSci bombing. I'll get you the other two."

"Thanks." He opened the folder as she left, flipping through the pages quickly. Then he shut it, tossed it onto the table with a slap and went to get some coffee. It was going to be a long day.

- - - - -

"I won't tell you again, Charlie, you are going to stay in this bed until you feel better."

"Dad, Larry left an hour ago, Don's at work, I have nothing to do. I'm going crazy, and I feel fine." Alan gave him a look. "I do. I feel much better- actually, I barely even feel sick. Really." He continued to stare. "At all," Charlie added, nodding emphatically.

Alan considered it. "Just to the store?"

"Just to get some ginger ale for my throat," he said quickly. "I'll be gone like- ten minutes."

"Fine." Charlie sprang out of bed, and went to his dresser, pulling out some clothes. "Hey, hey-" Alan said suddenly, grabbing him by the arm. "Promise me you're not going downtown. Don told me he dropped by to tell you about a case-"

"No, no," Charlie insisted, pulling his t-shirt over his head. "I'm not going to the FBI, I promise."

"Okay. Just don't push it, all right, I want you getting better, getting back to your routine. I know how being sick drives you nuts."

Charlie began to lace his sneakers and smiled. "Thank you."

- - - - -

"Professor Eppes! Professor?" Charlie stopped, hand hovering over the grocery store door. He sighed patiently when he recognized the well-dressed young man who was running pell-mell towards him.

"Good afternoon, Adrian."

The boy stopped, bracing his hands on his knees to catch his breath. "I'm sorry for chasing you down, is this a bad time?"

"I have a few minutes. What's up?"

"It's just I have this problem with my theorem. I think I made a serious error, because it started looking a lot more like a corollary, but I can't figure out an equation that might explain the error." He winced apologetically. "I was gonna ask you about this after class today, but it got canceled."

"I'm sorry, Adrian, I haven't been feeling well so I called off all my classes for today."

Adrian looked surprised. "I thought- I thought that you called it all off cause of…well, you know, cause of the bomb." He watched Charlie, wide-eyed.

"No…no, but I did hear about that. I'm glad no one was hurt."

"Yeah," Adrian shook his head in wonder. "It's so weird. I mean- why would someone want to blow up an empty lecture hall?"

Charlie nodded, thoughts momentarily elsewhere. Then he brought his attention back to Adrian. "Well listen. I'm still not completely recovered, and I don't want to get any of my students sick. But I'm hoping to keep both my classes tomorrow, so we can go over your theorem then. All right?"

Adrian looked relieved. "Okay. Thank you, professor Eppes." Charlie smiled as Adrian galloped across the parking lot, coat and tie flapping in the wind, then pushed the door open and went inside.

"This it, Charlie?" the cashier asked, eyeing the twelve-pack of ginger ale.

"That's it, Mr. Kroger. Thanks."

Smile lines appeared somewhere far beneath Mr. Kroger's beard. "You're a man now, Charlie. When are you going to start calling me Victor?"

He just smiled back. "How's Vanessa?"

"She's fine, thank you for asking."

Charlie leaned against the counter as Mr. Kroger rang up the case. He then noticed the Pac-Man machine standing across the room, and smiled a little. Mr. Kroger followed his gaze. "I can still see Don pounding away at that thing," he said.

Charlie turned around. "He was good, wasn't he?"

Mr. Kroger nodded. "Beat the all-time record. I typed him up a certificate myself." He smiled fondly. "It's still there, actually."

Charlie's eyebrows shot up. "Get out."

"Check it yourself, if you like." Charlie crossed the room and brought up the top scores list. Sure enough, in the number one slot: "DIEHARD DON". Charlie laughed, and he heard Mr. Kroger do the same, recalling out loud, "The night he made that score, the store was packed. He was probably here for hours. By the time he won, there were…oh, maybe twenty people standing around him. He was a real hero."

"Do you know what day that was?" Charlie asked, but he found it on the score list just as Mr. Kroger said it.

"October 14, '85. That was a day I'll never forget," Mr. Kroger said.

"Yeah," Charlie came quietly back to the counter. "Me too."

"And your total is $6.69. Charlie?"

"Huh?"

"Something wrong?"

"Uh…no. $6.69?" He handed Mr. Kroger a ten, then took his change, forcing a smile. "Take care, Mr. Kroger."

When he got outside, he pulled out his cell phone, and dialed with one hand, unlocking the car and swinging the ginger ale into the backseat with the other. "Hey, Dad it's Charlie. Look uh…I know I said I was going to come right back home, but it's-" he pulled the phone from his ear to check the time, "it's almost two o'clock, and I am starving. I'm going to get lunch with Larry…yeah- Dad, I know, but I feel fine…look, I'll be back in an hour, okay?…okay. I will. You too…Bye."

- - - - -

"Two suspects." Don pinned up a picture of a cold-looking man. "Jackson Greer, 32, black. Born in Montana, moved to California when he was 15. Charged with arson, possession of illegal explosives and firearms." He pinned up the next photo. "And TJ Pullman, 29, white. Born and raised in LA, Charged with possessing and selling illegal explosives and drug possession." He stood back, examining the two photos.

Megan tapped a finger on the back of her chair. "Both perfect scenarios for gang leaders."

"Exactly," Don said. "Now, I talked to the sate pen., and they told me without sufficient evidence, they can't move these guys. So for the time being they're still in LA, though I'm pushing for tightened security."

"Well, it would help if we could at least keep them from options," Colby pointed out. "I mean- trash-stabbing, laundry duty, kitchen duty…there's loads of loopholes they could be working through."

"Like I said, I'm working on it," Don said, pressing his palm to the board again. "Till then, we keep looking into these guys. There has got to be a connection between the three bombings. Ask around at the grocery store, the restaurant, CalSci campus. See if anyone there knows anything about these guys or ever saw them before they were incarcerated."

Colby stood up. "Do we have anyone talking to Greer and Pullman yet?"

"No, still processing the request. I'll send you and David as soon as we get cleared."

- - - - -

"I don't quite understand what you're trying to tell me here, Charles. You all ready forgave Don, even felt guilty for faulting him. How is it now you know he was at the arcade, that forgiveness is moot?"

Charlie shook his head, running his fingers restlessly through his hair. "It's not that, it's…I felt guilty because it wasn't Don's fault he didn't show. But I mean…he knew, he knew I needed him to walk me home, and he…he was playing video games? I just- I don't know…" He shook his head, leaning back in his chair, crossing his arms. At a loss.

Larry watched him for a few moments, then continued spreading cream cheese on a stack of crackers. "So what are you going to do about your new discovery?"

Charlie bit his lip. "I don't know…nothing, I guess. I mean what am I supposed to do? Hey Don, remember that thing that happened when I was ten? Yeah, well I just figured out you were playing Pac-Man at the time and, uh, I expect an apology. I mean, it's ridiculous Larry, this was twenty years ago. It shouldn't even be bugging me."

"You know, there is a common misconception that time heals wrong, when in fact, time just makes wrongs age. And I hate to tell you this, Charles, but grudges age really well."

Charlie sighed. "So what do you suggest?"

"I think if you talk to Don, you may actually get some closure. You might even find out that there's more to it than you think, and all the turmoil was for nothing. But you'll accomplish nothing by doing nothing. Aristotle said it best, 'All causes of things are beginnings; that to know a thing's existence is to know the reason why it is.' It basic causation, if you do not act you will not get results."

Charlie's head came up slowly. "Cause and effect."

"At it's most fundamental," Larry said fondly, and took a bite out of his cracker.

"Larry…why didn't I think of it?" Without giving him a chance to respond, Charlie left the table at top speed. By the time his chair fell over, he was all ready on his way out the door.

- - - - -

"All right…thank you. Thank you, yes. Agent Sinclair and Agent Granger will be there shortly." Don hung up the phone just as the door burst open and Charlie came running in.

"Don! Don, I think I may know how to track these guys down."

"Charlie what- aren't you supposed to be in bed?"

"Remember that theory," Charlie insisted, coming around the desk, all ready unrolling sheets of graphs and maps. "The one I tried to use in that arson case."

"The ELM fires?"

"No, the other one, the one in Pasadena."

"Oh right, you mean the Behavioral Choices-"

"Behavioral Decision Theory, yes. I don't know why I didn't think of it. I mean, this theory's somewhat new to me, I suppose. But I really think, despite all the proposed and, frankly credible fallacies found in the theory, I can distill it into a concise and explicit algorithm specifically applicable to this case."

"Okay, but…you're going to have to come up with some lemans terms for me, buddy, cause you tried to explain this whole thing when you finished it-"

"You said it looked impressive."

Don blinked. "Well…yeah, Charlie, your math always looks impressive, that doesn't mean I have any idea what you're talking about."

"Okay, uh…imagine a highway. And every car is unique, different brand, color, make. Now each car has its own destination, and there is no way you can guess exactly where it's going to go just by looking at it. However, there are limitations, such as gas stations and the distance itself. Also, there are rules that you know the car is going to have to follow: Speed limits, traffic lights, other cars."

"You're not going to see one car purposefully bashing into another car or driving into the grass."

"Barring lunacy, no."

"But people run red lights, speed-"

"Yes, but then the risks go up. So you calculate the probability of a car running a specific red light, taking into consideration traffic cams, number of cars in the vicinity, location of the nearest police station. And in the case of gangs, these people also have an agenda. If we can figure out what that is, we'll know where the car is going and the route will be all the easier to figure out."

Don nodded slowly. "I think I know where you're going with this. But there are maybe a couple hundred factors in a car, and like- a million in a person."

"Actually if you're talking possible factors, it's more like a million for a car and-" He grabbed a black marker, went to the whiteboard and wrote a ten with a little twenty-four next to it, "more like one septillion for a human being. Approximately, I haven't worked that one all the way through."

"And I guess you're going to tell me you can actually factor through one septillion possible motives and roadblocks?"

"Actually yes." Charlie paused a minute then added, "But, that would take probably ten years or so. For the time being, we're going to overlook the possibilities and stick with the probabilities. For one thing, we are going to assume that the person or persons in question are sane. That knocks off about a thousand possibilities right there."

"So basically, you're breaking people down into equations."

Charlie thought about that a moment, hesitating at the note of skepticism. "Well," he said slowly, "really anything can be broken in to numbers. People are profoundly more complex than most subjects, but…yeah." He shrugged, grinning a little. "Just…you know, do the math."

- - - - -