"She was lucky." Don turned away from the glass window into the Intensive Care Unit. "Doc says the worst of it was a concussion, wants to keep her overnight at least, maybe a few days." It didn't completely square with the splint on one wrist or the bulky white bandage across one side of Megan's face, but Don had learned long ago that appearances were deceiving. Look at what had just happened: Megan walking out of a completed crime scene, none of them expecting anything like this. The criminals they were after had just upped the ante. They were out for blood.

Don would be more than happy to give it to them.

His team felt the same way. "It's time for some serious leaning," David said, the anger smoldering deep.

"Keep it clean," Don felt obliged to say, though part of him ached for the chance to rip the answers out of the nearest person available. "We can't afford to let these guys walk on a technicality." He stared inside. The woman inside looked so still and the machines so cold. A nurse moved quietly from one side of the room to the other, adjusting this and that. It looked as incomprehensible as the suspects that had done this.

"This is crap," Colby announced. "How the hell do they do it? How do they know what we're doing? They finish every job literally minutes before we arrive, and they're sure as hell laughing when we roll up. How do they know?"

"That's it," Don said slowly. It hit him with the force of a small tsunami. "They know."

"Don?" David raised his eyebrows.

"They know," Don repeated. "How do they know? They time every operation so that they complete it just minutes before we arrive. That takes a lot of planning: an estimate of the time it takes for us to arrive at the scene. An estimate of how long it will take us to crack their stupid little codes. And, gentlemen, if they're leaving less than five minutes before we arrive, then they're not guessing. They know!"

"We have someone who's dirty?" Colby leaped to the obvious conclusion.

"Maybe." Don looked at each of them: David, with the anger smoking behind dark eyes and Colby, who wore hisfury like a badge upon his sleeve. "But it's only us three right here. You think one of us is dirty?"

"Or Charlie?" Colby blurted out, but immediately shook his head. "Not him. Who, then? Someone back at the office? A secretary, or someone? Somebody with access to a phone?"

"Always a chance, but there are easier ways," Don said. "Example: what if they stationed a plant outside FBI headquarters with a cell phone? We come running out of the building, leap into our cars, and speed away. A cell phone call later, and the criminals are in and out of the job. We show up just in time to hear the grateful citizenry complain that we're too late. That sound plausible?"

David nodded. "Works for me. And I like it a lot better than someone I know working against us. Next question: if that's how they do it, how do we get it to work for us? We've still got to catch these guys."

"Tapes," Colby said. "Our building has security cameras monitoring the plaza outside the entrance. We can get hold of the tapes covering a half hour before and after the phone calls, see if there's any person who shows up in all of them."

"Cutting it close, Colby," Don warned as the younger agent slid into his chair. David was already there, sitting around the table and Charlie was there too, furiously scribbling notes into a notebook. Don had already glanced over the incomprehensible symbols: it was Charlie's next lecture for the out of town professor's spoon-fed class. The previous lecture had gone well, Charlie assured him. The time before the previous call had been well-spent, even if it didn't do anything to solve this case. At least one thing turned out right. With luck, Megan might get to come home from the hospital tomorrow. I need to think about continuing the protection on her. That sedan aimed for her. Why? "Our next phone call could be any minute. Any luck?"

"Not sure," Colby replied with a hopeful I extended the parameters tone to his voice. "I didn't get any repeat suspects for all of the time periods in question, so I expanded the search to people using cell phones in the vicinity who could have called it in to the criminals. You know, in case they hired different people who would do it as a lark, not knowing the real story. Make it more difficult to identify the lookout."

"Good," Don grunted, knowing the younger agent was looking for his approval. "Anything?"

"I'm not sure. There were sixteen people that I found using their cells at the time that we exited the building last Friday. All of 'em could be innocent, but maybe…"

"That's your angle." Don handed that part of the investigation over to Colby as a reward. "Identify the people, and talk to them. Gently; don't lean. Get their permission to pull their cell records, see if anything looks promising. Anybody refuses, come back to me and we'll talk about a warrant." It was a long shot, but it was pro-active and that was what they needed right now. Not another phone call, taunting them about another crime being committed as they sat here deciphering codes. "David, you ready?"

"Been ready for the last fifteen minutes. This guy gonna call, or what?" More nerves on edge. Tinkering with the equipment on the table, not that it needed fussing with but David too needed something to do with his hands.

"We've got a consistent day, but not a time."

"It's all part of the variables," Charlie spoke up. "He hasn't called at the same hour twice, but it's always been on a Monday, Wednesday, or Friday. And it's always been daytime hours. Actually, they've all been after noon. After one o'clock."

"Considerate," Don grunted. "He waits until after lunch."

"Or perhaps there's a reason why," David mused. "He's got a wife and kids, maybe? A family who doesn't know what Daddy does for a living?"

"It would fit Megan's profile," Don agreed, when the phone rang. Don almost snatched it up, but held his hand above the handset, waiting for David to give him the go-ahead.

"Go."

Don forced himself to relax, to become calm. It might be a routine call, a false alarm. Or it could be their suspect calling to gloat and taunt. He picked up the phone, putting it on speaker. "Eppes."

"Are you the one solving the riddles?" Computer voice. It was the call.

Get this guy off-guard. "I'm the only one you'll get to talk to. Say what you have to say. Turn yourself in. We'll get you eventually."

"No. I'll speak to the one who solves the riddles."

"I solve them," Don lied with a poker face, hoping that the bluff would leach from his face into his voice, putting a restraining hand on Charlie's wrist. How did this guy know? The mathematician kept silent, his eyes round, watching his older brother work. Biting his lip. This was Don's world, and it was never so evident as now. Put him in front of a class room and Professor Charles Eppes was at home. Here, dealing with someone who could only be described as a criminal mastermind, talking to them on the phone: that was where Don excelled. He was in his element. Don was in control.

"Really." The computer generated voiced generated scorn. "Prove it. Cube root of 79,507, now."

Colby frowned, alarm showing, but Charlie looked up at the ceiling, then jotted something down on a scrap of paper and handed it to Don.

"Forty three," Don told the computer voice.

A moment to reflect, then: "The clue." Yes! Don allowed a small smile of triumph to reign. They were fooling the man on the other end of the phone line. "Listen carefully: it will be faxed to your office within five minutes." Click.

Don leaned back in his chair, willing his hand not to shake. "Alert the secretarial staff."

"On it." Colby was out of his chair, eager for movement.

"David?"

"As usual, not long enough." David tapped a few more buttons disconsolately on his equipment. "This guy knows what he's doing. This is the faster locator box in town, and it's still not fast enough for a trace. And it wouldn't surprise me if this cat is sending the signal through a couple of different relay stations, just to confuse the issue."

"More 'profiling', David? Isn't that Megan's job?"

Snort. "Common sense. This guy wants to make fools of us, show us how smart he is. I'd say he's succeeding."

"But he's not," Charlie put in.

Don lifted his eyebrows. "What do you mean?"

Charlie shook his head. "Don, he knows a lot about tech equipment, and he's clever, but he's not very smart. Don, the codes he's sending are downright elementary. When I did stuff for the NSA, I didn't even bother to teach this sort of code deciphering because it was too easy. Anyone using a code like this would have been laughed out of the business."

"After they got shot and killed," David murmured under his breath.

Charlie tossed him a glance that reluctantly admitted the accuracy of Sinclair's statement. "But he does do his homework. I'll bet that he's already planned out his next three crimes, has gathered information on each of them or is the process of doing so. He thinks ahead. He's like a chess player, planning out the sequence of events several steps in advance."

Don saw what his younger brother was getting at. "And if he's thinking out a plan ahead of time, we can deduce that plan ahead of time. We can predict his next move."

"Right. All I need are enough variables to reduce the uncertainty. I already have a date: Mondays, Wednesdays, and Fridays. And I'm working on some multi-variate analysis to try to narrow down the location for you. My computer back at my office has some stat packages that would make it easier…" Charlie let his voice trail off hopefully.

Don nodded. "Let's get this current code to bed, and I'll have someone take you back. You think you can have some predictions for us before Friday?"

Charlie shrugged, unwilling to commit himself. "I can try. I may not have enough data points to reduce the uncertainty to a realistic sample."

Colby burst back into Don's office, paper in hand. "Got it!" And: "it's a whopper. This thing looks crazy. You sure you're going to be able to solve it, Charlie?"

"Let me see it." Don intercepted the sheet of paper, scanning the letters. Not a one made sense. He thrust it at Charlie. "Do your thing, buddy."

Charlie accepted the paper, his chin set. He perused it, rubbing his chin absently. He shrugged, shaking his head dolefully. "What did I tell you? Simple."

.MT NWQTEWX ZM WNWLS RZC EEWM ZM EEBF EETS T

.CBXZM OFZEF'Z NRZK MB NWQTEWX ZM CXBWN

VNBEEZX IZTEETA IWM WQBL

.EETMV NWQWI VT MBLM HAZH B XWFBEY WQBL T

Don glanced at his watch for the fiftieth time, and then glared at the door that separated him from his brother. Charlie wanted it that way, claimed that Don and the others distracted him while he was working. The music in the headphones didn't, the noise from the street below didn't, but three men sitting quietly staring at his back would.

Twenty minutes. The previous time had been fourteen and change. 'Simple' Charlie had called it. Not so simple, was it, buddy? Not this time. Hurry it up. Somewhere, someone was getting robbed.

Colby had tapped the computer in the corner of the room to slave it to the outside security cameras. "Scanning," he muttered, looking for anyone using a cell phone. "Bumper crop of 'em. Tell me I'm seeing a guy with two, one at each ear. What is it, a cheap conference call?"

"Any look familiar? Any duplicates from any of the tapes?"

"A couple. I'm not sure; I'll need to pull up the other tapes to be certain. Maybe that guy." He pointed to a figure on the screen.

Both Don and David leaned over his shoulder. "Don't know him," Don reported.

"I do," David said. "That's Henderson, from Accounting. Makes a game of harassing me over my expense report."

"Hey, I sign that expense report. What's his problem?"

"Beats me. Maybe it's just his way of sharing the love."

"Any chance—?"

"Somewhere between slim and none," David assured him. "Besides, he's got a cubicle by himself and a view of the parking lot. It'd be easier for him to stay inside and watch us scurry out to our cars, then call. Rule him out, Don."

"Least he's got an excuse for being in the area. Is that a cigarette he's lighting up? Doesn't he know that smoking'll kill him?"

"Makes me grateful that all Federal buildings are smoke-free," David smirked. "Always knew I didn't like him."

Don looked at his watch again, then at the door. "C'mon, c'mon, buddy. You kept saying it was simple. What's the hold up?"

As if in answer, the door opened and Charlie emerged, flushed with excitement. "This one had a new twist. The suspect wrote it backward, and that threw me off for a minute or two. And, Don, this one's different. Look." He handed over his answer sheet.

I HAVE PLACED A BOMB THAT IS NEVER STILL. HAVE TEN MILLION DOLLARS READY TO DELIVER AT FOUR O'CLOCK TODAY. I WILL CALL TO TELL YOU WHERE TO DELIVER IT.

"What the hell?" Disbelief turned Don's voice harsh. "What the hell is a bomb that's never still? What kind of stupid ass riddle is that?"

"And it's already two o'clock," Colby added. "There's no way we could get ten million by four PM. This guy is crazy. What do we do with this?"

Don closed his eyes, praying for divine inspiration. "Notify LAPD. Get the bomb squad ready to go on a moment's notice. And think, dammit! What's never still? Where is the damn bomb?"

"A river," Charlie said thoughtfully. "The ocean. Bodies of water. They're never still."

"There are miles of coastline to search," David said, horrified. "We'll never get to it in time. We can't search every bag on every beach from Santa Monica to Laguna!"

"He's counting on it," Colby ground out. "He knows that we haven't a chance."

"Start the bomb squad to the beaches," Don ordered. "Any hunches which one…?" he trailed off, thinking. "You're right; he knows we wouldn't have a snowball's chance in hell."

"Don?"

"Not the beach. Not the ocean. That's too easy for this guy, too straight-forward. He's trying to make fools of us. He's put the bomb where we can find it, if only we're clever enough. He's always given us a 'chance'," Don explained. "We've been too slow to get to the scene, every time, but there's been a chance. If he put the bomb at the shore, we don't have that chance. It's not there. He would have given us a better clue."

"If it's not the shore, then where? What else is never still besides the ocean?"

"Busses." Don grinned without humor. "The busses keep on going through the city. They don't stop until they go back to base for the night, when the city slows down. The same hours that this guy keeps, so do the busses." He leaned forward. "Have the bomb squad report to the central bus terminal, and have every single bus in this city pass through there for inspection. We have a bomb to find, gentlemen!"