Colby was reminded of the old saw that ninety five percent of investigative work was drudgery. It never seemed so true as it did now. He and David were trudging from office to office, building to building, trying to find someone who had seen the pair enter the supposedly vacant office where the victim had been found. It was a low rent district, and those people tended to keep what they saw to themselves. The witnesses saw plenty, weren't willing to share, and without some sort of lever the FBI agents had no way to pry anything loose.

"I'm tempted to run a wants and warrants on some of these guys, just to see if we can shake something outta these dudes," Colby grumbled. "Something like a verbal headlock, ya know?"

"It may come to that," David agreed. "Forensics come up with anything?"

"Them? Hah." Colby snorted. "They're still babbling about Charlie coming down to talk to them. Like he doesn't come in every week, whenever Don calls. He's a regular."

"Yeah, but he doesn't usually talk to the Forensics guys,' David reminded him. "For them, that's a big deal. Like some sort of Einstein, only in math."

"I can't follow Einstein, either, David."

David chuckled. "Just repeat after me: e equals mc squared. e equals mc squared."

"And that's supposed to help us find this bozo how?"

"Worked for Einstein—hey! Who's that over there?"

'That' was a middle-aged woman dropping a letter into the mailbox that serviced the office of the dead man. If she had been wearing something postal, David would have ignored her. The quantity of advertising gimmickry in letters had long since outnumbered the quantity of first class mail. But since she was in a skirt that was too short for her overweight body and a sweater that covered up the worst of it, David was understandably curious as to what sort of mail was being delivered. "Ma'am! Ma'am! Wait a minute."

They hustled back to the building, pulling out badges.

"Agent Sinclair, FBI," David identified himself. "Can I ask what you were doing?"

The woman looked at him strangely. "I was putting that letter into the box for whatever moron works there. What's the matter? The FBI investigating misplaced letters these days?"

"Only if they go into that particular mailbox." Colby reached in and retrieved the letter. The dead man wouldn't mind, and this was a Federal case with Federal postal privileges that included retrieving mail addressed to dead victims. "Mind telling us your name?"

"Delores Kramowitz. I work in the next building over. What's going on here?"

"How did you get this letter, Ms. Kramowitz?"

"Good question. Try asking the mailman. She's the one who screwed it up, putting that letter in my box instead of the right one. Now I gotta walk all the way over here to get it where it belongs. They oughta' pay me instead of her."

David eyed the distance: less than one hundred yards from the woman's building, even including the walk from where he thought the office might be to the sidewalk. Life could be tough for the able-bodied…

"Is this the only letter that you've gotten for this address?" he asked politely.

"Naw. Whaddaya think, that postgirl actually knows what she's doin'? She's always sticking this guy's mail into my slot." The woman snorted. "You want more? I got more. It's in my trash bin. You can have it, if you want to come get it."

David looked at Colby. "If the postal service thought that the vic's office was empty, that someone has gotten the address wrong…"

"The postal carrier might have tried to leave the letter where she thought that it ought to go." Colby finished the statement, agreeing. "Ma'am, where is your office? We'd very much like to see whatever other letters came for this man."

The gossip alert meter went ping in the woman's head. Her eyes widened, and she fought down a gleeful grin. "He a terrorist, or something? You are FBI, right? Regular G-men?"

"Yes, ma'am, we are." David flashed his ID one more time, slowly enough so that the L.A. sunlight could glint off of the gold. If the woman was going to gossip, she might as well get it right. "The letters?"

"The trash," the woman announced, clearly excited that her co-workers would see her in the company of the two FBI agents. "Gotta hurry, so they don't empty the bins."

There were four letters that they were able to retrieve from the woman's waste paper basket. Why she had chosen to hand deliver one and not the rest of the envelopes was a mystery that none of them had a snowball's chance in hell of solving. Three of the missives were addressed to 'occupant' but the fourth: Mr. Artemus Gordon.

"Bingo," said Colby, reaching for it.

David stayed his hand. "How do you know?"

"Look at the name, dude. Gotta be. How many spooks you know have that particular name?"

"How many spooks use their real name, Colby?"

"What real name?" Colby snorted. "This guy was into old TV series from the sixties."

David blinked. "And you know this because of the name—?"

"Wild Wild West, man." Colby shook his head. "You, with all your good taste, don't even know one of the seriously great pop culture icons?"

David now stared. "You need to get a life, Colby."

"And what is it that I'm supposed to be looking at?" Don Eppes was being serious. Seriously confused, but serious nonetheless.

Confused on several different levels. Not only was he confused as to what the forensics specialist was trying to show him, but he was confused about the forensics specialist him—or her—self. And he privately thought that Terry Gatsbacher liked it that way. Lean body with shapeless clothes covering over what curves may or may not have existed. Pierced ears, one on the left and two on the right. Heavy on the mascara, and a voice that would either make a castrati jealous or Marlena Dietrich melt, take your pick. Gender confusion to the max.

Did it really matter? Don's private life tended to run on empty most of the time, but even he wasn't that desperate. And, to be honest, he was afraid of what he might find under those sweats. There were some things that a field agent truly didn't need to investigate under any circumstances. Gatsbacher's private life was one of them.

Back to business.

"After your brother finished talking about this," Terry was saying, "I took another look at the crystals that came out of the crime scene. I took a long and hard look."

"And you found—?" Gatsbacher, Don decided, could be as long-winded as Charlie.

"I found two types of crystals," Gatsbacher announced proudly. "Isn't that great?"

"Absolutely." Don had no idea what he was agreeing to. "Why is it so great?"

Gatsbacher looked at him just like his high school teachers had, right after they discovered that Don was no Charlie Eppes. It was that combination of surprise, disgust, and a healthy dollop of pity that did it. Don cringed inside. Dammit, it's not as though I'm an idiot, here! Not everyone can be genius material.

"I've uncovered the motive for the murder." Gatsbacher took pity on the field agent.

"Enlighten me." Before I slap you with the same charge of obstructing justice that I threatened Charlie with.

"There are two types of crystals here," Gatsbacher repeated, unable to believe that anyone couldn't understand the significance of the discovery. "Two types. With differing densities. One boils at four hundred and twelve degrees Celsius—"

"I heard you," Don said impatiently. "Why is that important? What's so important about the boiling point of this stuff?"

"It's not the boiling point—"

"You just said that it was."

"No, it's the concept behind the differing points—"

"What concept?"

"That they're different—"

"And—?" Don was getting thoroughly frustrated. Next step: get out his gun, take off the safety, and aim!

"It's the key."

"The key." What was it with all these scientific types? Couldn't they communicate in plain English? "The key to what? Some locker in the downtown bus station? I need a little more explanation here, Terry. Humor me. Start from the beginning."

Gatsbacher heaved a sigh laced with leftover onions from his/her lunchtime meal. Don held his breath.

"When your brother came in, he explained that one way to pass information is to pass the information in a coded format one way, then send the key to de-crypting that information in another. This enhances the secrecy. Even if the enemy gets the information, they won't be able to decode it without the key. The paperweight that exploded in the victim's office contained the key."

Now Don was able to leap onto the train of knowledge. "And you have that key. You found it in the crystals."

"Right!" Gatsbacher beamed; the slow student had finally understood the lesson. "But not quite."

"But not quite," Don repeated. "How not quite?"

"We only have part of the key. Not quite half, maybe closer to a quarter of the crystal. Rather ingenious, actually. It was embedded as part of the decoration of the paperweight. We're not yet certain what happened to the other part. The key cracked, and the larger part was lost."

"Taken by the other man?"

"That I couldn't say." When Gatsbacher looked prim, he/she looked effeminate. But Don wasn't about to assign a gender just yet. Shudder. "It's very possible—likely, even—that the other half of the crystal was shattered in the explosion. Which is bad news for you, Don. Without that key, no one will be able to decipher whatever code it belonged to. Not you, not me; not anyone. Sandy is working on the other parts of the crystal, to see if there are differences in the density, any pieces that we can put back together again to get a hint as to what it said. Sandy and I are going to have to get downright personal with it." Terry looked positively gleeful at the thought.

Good. Sandy—another person of indeterminate sex, and a very close friend of Terry Gatsbacher—was welcome to discuss his/her findings in a fast email to Don. The field agent beat a hasty retreat before he was subjected to any further scientific or gender discoveries.

All too soon, the scene once again became the Forensics lab. This time the participants included David, Colby, and Megan, as well as Terry Gatsbacher and Don. Don almost had to force himself to attend.

"It's your letter; you open it," Don offered.

It wasn't generosity that prompted the team leader. It was fear. "What if it contains anthrax powder?" Colby asked.

"I've already irradiated it," Terry Gatsbacher said cheerfully. "No danger there." David and Colby, upon arrival back at FBI headquarters, had hustled down to the Forensics lab to investigate their new acquisition. Colby had notified Don and Megan of the discovery, while David had coerced Gatsbacher into leaving the latest and greatest forensic experiment in order to move forward with the current case. All four field agents kept nervous hands inside pockets; the bubbling liquids in beakers looked about to explode into little fountains of rainbow death. Don himself saw absolutely no connection between this scene and his memories of high school chemistry with Mr. Kostmeyer beyond the fact that both episodes appeared to contain great danger to a certain Don Eppes. Don fingered the keys in his pocket, just to have something to wrap his fingers around.

"Good." Colby slit the letter open, tapping it to see inside.

"Of course, there could be something impervious to irradiation," Terry added.

All of them backed away: Don, Colby, David, and Megan.

"But probably not." Terry peered at the now open envelope and inhaled. "There's no powder inside. No perfume. Just a piece of paper." Terry reached inside.

"Wait!" Don all but shouted. "Fingerprints?"

Terry looked disgustedly at the senior field agent. "Teach your grandma how to bake cookies," he/she sneered, waving latex-covered hands. "Besides, people this careful, you think they're going to be considerate enough to leave prints for us?"

"Stranger things have happened," Don muttered, thinking that one of those stranger things was standing right in front of him.

Terry Gatsbacher was correct; there were no fingerprints, and a moment's worth of dusting proved that.

And there was another strange thing: the letter inside. It was a single piece of paper, covered with symbols. Very odd symbols.

Colby stared at it. "Looks Greek to me," he quipped. "Isn't that the Greek symbol for alpha?"

"Some of it looks like Hebrew," Don offered doubtfully.

"Some Cyrillic stuff there," Gatsbacher added with entirely inappropriate good humor. "In fact, I think I see at least four different alphabet systems. Hm, maybe more. Isn't that Goa'uld?"

Megan glared at him. "That's fictional. There's no such thing."

"Doesn't matter. You're going to need the Translations department to make heads and tails out of this one. It's a mess. Every other word is in a different language. It'll take four different translators to put this into English."

"Not Translations." Don kept staring at the undecipherable paper. It was trying to talk to him, tell him what the hell this was all about.

"Not Translations? Who, then?"

"A certain mathematician."

But a trip to the local high-powered university where that certain mathematician spent most of his working hours needed to be postponed for a short visit with someone that Don would rather not talk with. Don hadn't a clue as to how the CIA agent knew to turn up at that exact moment. Guess it's why they call 'em 'spooks', he mused.

Tanner wasted no time. He held out his hand. "The letter, Special Agent Eppes," he requested. "It's CIA business."

Don wasn't cowed. "Right now it's FBI business, Agent Tanner," he returned in the same flat tones. "This is still a homicide investigation."

"This is national security."

"Which is why the FBI is handling it, rather than the LAPD."

"You haven't the facilities to handle this, Special Agent Eppes."

Don folded his arms. "Care to elaborate, Agent Tanner?"

Tanner pointed at the copy of the letter in Don's hand. "That particular type of code is standard in my line of work. Without my resources, you'll never be able to decipher it."

"Neither can you," Don returned mildly. "The key was destroyed in the explosion at the crime scene. Without that key, no one can solve it."

"I think we have another copy of the key," Tanner said, daring Don to disagree.

"Really?" Don allowed disbelief to color his tones. He smelled a ruse. On the other hand, they were supposed to be working together… He smiled instead, giving the impression of we're all friends here. "I can't give you the original, Mr. Tanner. That's evidence. But I'll make you a copy if you'll promise to let us know what it says as soon as you find out. I'm sure that it will help us both to get what we need." And it will be very interesting to hear what sort of lies you come back with.

"Done." Tanner held out his hand to shake on it.

Shaking that man's hand was not what Don wanted to do. He compromised by putting a copy of the letter into it. "I'm looking to hearing your version of the information," he said. As well as my brother's…

"Are you sure that he's got a cell phone?" Megan's attempt at humor wasn't the greatest, but Don wasn't in the mood for riotous laughter.

"Oh, he's got one," he replied, stomping on the brake just a little harder than he needed to in order to halt before the red light. "Keeping the battery charged is another story altogether."

Megan turned her attention back to the road, wrinkling her nose at the VW Beetle who thought that stopping at red lights was for wusses. "You sound pretty certain that Charlie can crack the code on that paper. I don't know, Don. I mean, Charlie's good, but this thing has at least four different languages on it. How is he ever going to figure it out? Especially if it's not in English?"

"I have confidence in him," Don said stoutly, wondering the same thing. I mean, Charlie's good, but is he good enough? There's no key to crack this code with, no matter the CIA says. Can anyone solve it?

Gotta have faith.

He glanced in the rear view mirror automatically, gauging the traffic around him. The hair on the back of his neck stood up—was that the same silver sedan that had been behind him six blocks and four turns ago? Naw, couldn't be. Silver was the new color du jour; every other car on the street was silver. But there were the same two dark heads in the front seat, and his 'spidey sense' wasn't just tingling, it was sending up full-fledged 'danger, Will Robinson' signals—

"Megan, I'm going to take a swing around the block," he said, forcing casualness into his voice.

Megan wasn't fooled. She peered backward, able to twist around in her seat. "Silver sedan, license plate 4CFK212?"

"I can't see the plates, but it's that silver sedan."

"I'll run the plates."

"I could be wrong."

"In which case I'll have to shoot you for making me nervous." Megan called it in, getting the answer back in mere minutes. "Rental car. And it's still behind us."

"After three turns around the same block. Somehow I don't think they're lost, do you?" Don tightened his grip on the steering wheel. "Call for back up. Maybe we can take these guys out, see what they're up to."

"You think it has anything to do with this case?" Megan wondered.

"Possible. Neither of us has any court cases coming up, no reason to kill us off before a lurid trial. You dump anyone recently?"

"Yeah, but he didn't drive as well as the guy in the sedan. That was part of the reason I dumped him; he almost got us both killed in a car accident. You?"

"You had a date? And you didn't tell me?"

"You're not my mother, Don."

"You don't even tell her, Megan."

"Got me there," Megan conceded. "You?"

"Me, what?" Don turned the corner, trying not to look as though he was acting like bait for the sedan behind them.

"Dump anyone recently?"

"Hah." Slow down, don't pull away too fast. "The tales of my love life could fit on a single sheet of paper right now, triple-spaced. Where's the back up?"

Megan listened to her cell. "Five minutes. They're stuck on La Cienega."

"Five minutes! What do they think this is, the watched pot that never boils? We're the FBI, for cripes' sake!"

"You think you can string our friends along for five minutes?"

"Only if they're stupid," Don grumbled. "How do they look?"

"Not stupid. Don, they're increasing speed, pulling up on us."

"You think they've realized they've been made?"

"Yeah." Megan's voice trailed off…

Only to erupt: "Duck! They've got a gun!"

Don wrenched the wheel sideways, diving below the dashboard. Bullets sprayed the window, shattering it as badly as the crystalline key to the letter. Don stomped on the brakes, allowing the attacking sedan to shoot ahead of them and out of easy target range.

Megan was already on the radio. "Shots fired! Shots fired! We need immediate assistance!"

Good: the Suburban was still in working condition. Little breezy, but working. Don poured on the power, trying to catch up to the rental sedan. He could do it, he could do it…

A stroller and a young mother stepped off of the curb into the path of the oncoming sedan. She realized her mistake, pulling back with a shriek.

The sedan got past. The Suburban, wider body, never would. It was a choice between catching the rental sedan and killing the stroller-bound infant. It was a choice between a young, innocent life and national security: lose-lose situation. Don made the call. Don once again stomped on the brakes, cursing.

The sedan roared off down the road. And, in the background, sirens screamed, signalling the impending arrival of reinforcements.

Don glared after the sedan, then favored the direction of the sirens with the same anger. "Little late, guys."