"Now, you have some sort of, er, mathematical proof for each one of these assertions?" Comstock asks. Math isn't his bag, but running meetings is, and what Waterhouse has just chalked up on that board looks, to him, like the rudiments of an agenda. And Comstock feels a lot better when he has an agenda. Without an agenda, he's like a grunt running around in the jungle without a map or a weapon.

"Well, sir, that's one way to look at it," Waterhouse says after some thought. "But it is much more elegant to view all of these as corollaries stemming from the same underlying theorem."

"Are you telling me that you have succeeded in breaking Azure? Because if so, congratulations are in order!" Comstock says.

"No. It is still unbroken. But I canextract information from it."

This is the moment where the joystick snaps off in Comstock's hand. Still, he can pound haplessly on the control panel. "Well, would you mind taking them one at a time, at least?"

"Well, let's just take, for example, Assertion Four, which is that Azure/Pufferfish has something to do with mining." Waterhouse sketches out a freehand map of the Southwest Pacific theater of operations, from Burma to the Solomons, from Nippon to New Zealand. It takes him about sixty seconds. Just for grins, Comstock pulls a printed map out of his clipboard and compares it against Waterhouse's version. They are basically identical.

Waterhouse draws a circle with a letter A in it at the entrance to Manila Bay. "This is one of the stations that transmits Azure messages."

"You know that from huffduff, correct?"

"That's right."

"Is that on Corregidor?"

"One of the smaller islands near Corregidor."

Waterhouse draws another circle-A in Manila itself, one in Tokyo, one in Rabaul, one in Penang, one in the Indian Ocean.

"What's that?" Comstock asks.

"We picked up an Azure transmission from a German U-boat here," Waterhouse says.

"How do you know it was a German U-boat?"

"Recognized the fist," Waterhouse says. "So, this is the spatial arrangement of Azure transmitters-not counting the stations in Europe that are making Pufferfish transmissions, and hence, according to Assertion One, are part of the same network. Anyway, now let us say that an Azure message originates from Tokyo on a certain date. We don't know what it says, because we haven't broken Azure yet. We just know that the message went out to these places." Waterhouse draws lines radiating downward from Tokyo to Manila, Rabaul, Penang. "Now, each one of these cities is a major military base. Consequently, each is the source of a steady stream of traffic, communicating with all of the Nipponese bases in its region." Waterhouse draws shorter lines radiating from Manila to various locations in the Philippines, and from Rabaul to New Guinea and the Solomons.

"Correction, Waterhouse," Comstock says. "We own New Guinea now."

"But I'm going back in time!" Waterhouse says. "Back to 1943, when there were Nip bases all along the north coast of New Guinea, and through the Solomons. So, let us say that within a brief window of time following this Azure message from Tokyo, a number of messages are transmitted from places like Rabaul and Manila to smaller bases in those areas. Some of them are in ciphers that we have learned how to break. Now, it is not unreasonable to suppose that some of these messages were sent out as a consequence of whatever orders were contained in that Azure message."

"But those places send out thousands of messages a day," Comstock protests. "What makes you think that you can pick out the messages that are a consequence of the Azure orders?"

"It's just a brute force statistics problem," Waterhouse says. "Suppose that Tokyo sent the Azure message to Rabaul on October 15th, 1943. Now, suppose I take all of the messages that were sent out from Rabaul on October 14th and I index them in various ways: what destinations they were transmitted to, how long they were, and, if we were able to decrypt them, what their subject matter was. Were they orders for troop movements? Supply shipments? Changes in tactics or procedures? Then, I take all of the messages that were sent out from Rabaul on October 16th-the day after the Azure message came in from Tokyo-and I run exactly the same statistical analysis on them."

Waterhouse steps back from the chalkboard and turns into a blinding fusillade of strobe lights. "You see, it is all about information flow. Information flows from Tokyo to Rabaul. We don't know what the information was. But it will, in some way, influence what Rabaul does afterwards. Rabaul is changed, irrevocably, by the arrival of that information, and by comparing Rabaul's observed behavior before and after that change, we can make inferences."

"Such as?" Comstock says warily.

Waterhouse shrugs. "The differences are very slight. They hardly stand out from the noise. Over the course of the war, thirty-one Azure messages have gone out from Tokyo, so I have that many data sets to work with. Any one data set by itself might not tell me anything. But when I combine all of the data sets together-giving me greater depth-then I can see some patterns. And one of the patterns that I most definitely see is that, on the day after an Azure message went out to, say, Rabaul, Rabaul was much more likely to transmit messages having to do with mining engineers. This has ramifications that can be traced all the way back until the loop is closed."

"Loop is closed?"

"Okay. Let's take it from the top. Azure message goes from Tokyo to Rabaul," Waterhouse says, drawing a heavy line down the chalkboard joining those two cities. "The next day, a message in some other crypto system-one that we have broken-goes from Rabaul to a submarine operating out of a base here, in the Moluccas. The message states that the submarine is to proceed to an outpost on the north coast of New Guinea and pick up four passengers, who are identified by name. From our archives, we know who these men are: three aircraft mechanics and one mining engineer. A few days later, the submarine transmits from the Bismarck Sea stating that it has picked those men up. A few days after that, our waterfront spies in Manila inform us that the same submarine has showed up there. On the same day, another Azure message is transmitted from Manila back up to Tokyo," Waterhouse concludes, adding a final line to the polygon, "closing the loop."

"But that could all be a series of random, unconnected events," says one of Comstock's math whizzes, before Comstock can say it. "The Nips are desperate for aircraft mechanics. There's nothing unusual about this kind of message traffic."

"But there is something unusual about the patterns," Waterhouse says. "If, a few months later, another submarine is sent, in the same way, to pick up some mining engineers and some surveyors who have been trapped in Rabaul, and, upon its arrival in Manila, another Azure message is sent from Manila up to Tokyo, it begins to look very suspicious."

"I don't know," Comstock stays, shaking his head. "I'm not sure if I can sell this to the General's staff. It's too much of a fishing expedition."

"Correction, sir, it wasa fishing expedition. But now I'm backfrom the fishing expedition, and I've got the fish!" Waterhouse storms out of the room and down the hall toward his lab-half the fucking wing. Good thing Australia is a big continent, because Waterhouse is going to take all of it if he's not held sternly in check. Fifteen seconds later he's back with a stack of ETC cards a foot high, which he pounds down on the tabletop. "It's all right here."

Comstock has never fired a gun in his life, but he knows card-punching and -reading machinery like a jarhead knows his Springfield, and he's not impressed. "Waterhouse, that stack of cards carries about as much information as a letter home to Mom. Are you trying to tell me-"

"No, this is just the summary. The result of the statistical analysis."

"Why the hell did you punch it onto ETC cards? Why not just turn in a plain old typed report like everyone else?"

"I didn't punch it," Waterhouse says. "The machine punched it."

"The machine punched it," Comstock says very slowly.

"Yes. When it was done performing the analysis." Waterhouse suddenly breaks into his braying laugh. "You didn't think this was the raw inputs, did you?"

"Well, I-"

"The inputs filled several rooms. I had to run almost every message we have intercepted through the whole war through this analysis. Re member all those trucks I requisitioned a few weeks ago? Those trucks were just to carry the cards back and forth from storage."

"Jesus Christ!" Comstock says. He remembers the trucks now, their incessant comings and goings, fender-benders in the motor pool, exhaust fumes coming through his window, the enlisted men shoving heavy carts up and down the hallways, laden with boxes. Running over people's feet. Scaring the secretaries.

And the noise. The noise, the noise, from Waterhouse's goddamned machine. Flowerpots vibrating their way off file cabinets, standing waves in coffee cups.

"Wait a sec," says one of the ETC men, with the nasal skepticism of a man who has just realized he's being bullshitted. "I saw those trucks. I saw those cards. Are you trying to get us to believe that you were actually running a statistical analysis on each and every single one of those message decrypts?"

Waterhouse looks a little defensive. "Well, that was the only way to do it!"

Comstock's math whiz is homing in for the kill now. "I agree that the only way to accomplish the analysis that is implied by that"-he waves at the mandala of intersecting polygons on Waterhouse's map-"is to go through all of those truckloads of old decrypts one by one. That is clear. That is not what we are objecting to."

"What are you objecting to, then?"

The whiz laughs angrily. "I'm just worried about the inconvenient factthat there is no machine in the whole world that is capable of processing all of that data, that fast."

"Didn't you hear the noise?" Waterhouse asks.

"We all heard the goddamn noise," Comstock says. "What does that have to do with anything?"

"Oh," Waterhouse says, and rolls his eyes at his own stupidity. "That's right. Sorry. Maybe I should have explained that part first."

"What part?" Comstock asks.

"Dr. Turing, of Cambridge University, has pointed out that bobbadah bobbadah hoe daddy yanga langa furjeezama bing jingle oh yeah," Waterhouse says, or words to that effect. He pauses for breath, and turns fatefully towards the blackboard. "Do you mind if I erase this?" A private lunges forward with an eraser. Comstock sinks into a chair and grips its arms. A stenographer reaches for a benzedrine tablet. An ETC man chomps down on a number two lead pencil like a dog on a drumstick. Strobes flash. Waterhouse grabs a fresh stick of chalk, reaches up, and presses its tip to the immaculate slate. The crisp edge of the stick fractures with a slight pop, and a tiny spray of chalk particles drifts to the floor spreading into a narrow parabolic cloud. Waterhouse bows his head for a minute, like a priest getting ready to stride up the aisle, and then draws a deep breath.

The benzedrine wears off five hours later and Comstock finds himself sprawled across a table in a room filled with haggard, exhausted men. Waterhouse and the privates are pasty with chalk dust, giving them a ghoulish appearance. The stenographers are surrounded with used pads, and frequently stop writing to flap their limp hands in the air like white flags. The wire recorders are spinning uselessly, one reel full and one empty. Only the photographer is still going strong, hitting that strobe every time Waterhouse manages to fill the chalkboard.

Everything smells like underarm sweat. Comstock realizes that Waterhouse is looking at him expectantly. "See?" Waterhouse asks.

Comstock sits up and glances furtively at his own legal pad, where he hoped to draw up an agenda. He sees Waterhouse's four assertions, which he copied down during the first five minutes of the meeting, and then nothing except a tangled field of spiky doodles surrounding the words BURY and DISINTER.

It behooves Comstock to say something."This thing, the, uh, the burying procedure, that's the, uh-"

"The key feature!" Waterhouse says brightly. "See, these ETC card machines are great for input and output. We've got that covered. The logic elements are straightforward enough. What was needed was a way to give the machine memory, so that it could, to use Turing's terminology, bury data quickly, and just as quickly disinter it. So I made one of those. It is an electrical device, but its underlying principles would be familiar to any organ maker."

"Could I, uh, see it?" Comstock asks.

"Sure! It's down in my lab."

Going to see it is more complicated. First everyone has to use the toilet, then the cameras and strobes have to be moved down to the lab and set up. When they've all filed in, Waterhouse is standing next to a giant rack of pipes with thousands of wires hanging out of it.

"That's it?" Comstock says, when the group is finally assembled. Pea-sized drops of mercury are scattered around the floor like ball bearings. The flat soles of Comstock's shoes explode them into bursts rolling in all directions.

"That's it."

"What did you call it again?"

"The RAM," Waterhouse says. "Random Access Memory. I was going to put a picture of a ram on it. Y'know, one of those sheeps with the big huge curly horns?"

"Yes."

"But I didn't have time, and I'm not that good at drawing pictures." Each pipe is four inches in diameter and thirty-two feet long. There must be a hundred of them, at least-Comstock is trying to remember that requisition that he signed, months ago-Waterhouse had ordered enough drain pipe to plumb a whole goddamn military base.

The pipes are laid out horizontally, like a rank of organ pipes that has been knocked flat. Stuck into one end of each pipe is a little paper speaker ripped from an old radio.

"The speaker plays a signal-a note-that resonates in the pipe, and creates a standing wave," Waterhouse says. "That means that in some parts of the pipe, the air pressure is low, and in other parts it is high." He is backing down the length of one of the pipes, making chopping motions with his hand. "These U-tubes are full of mercury." He points to one of several U-shaped glass tubes that are plumbed into the bottom of the long pipe.

"I can see that very plainly, Waterhouse," Comstock says. "Could you keep backing up to the next one?" he requests, peering over the photographers' shoulder through the viewfinder. "You're blocking my view-that's better-farther-farther-" because he can still see Waterhouse's shadow. "That's good. Hit it!"

The photographer pulls the trigger, the strobe flares.

"If the air pressure in the organ pipe is high, it pushes the mercury down a little bit. If it's low, it sucks the mercury up. I put an electrical contact into each U-tube-just a couple of wires separated by an air gap. If those wires are high and dry (like because high air pressure in the organ pipe is shoving the mercury down away from them), no current flows. But if they are immersed in the mercury (because low air pressure in the organ pipe is sucking the mercury up to cover them), then current flows between them, because mercury conducts electricity! So the U-tubes produce a set of binary digits that is like a picture of the standing wave-a graph of the harmonics that make up the musical note that is being played on the speaker. We feed that vector back to the oscillator circuit that is driving the speaker, so that the vector of bits keeps refreshing itself forever, unless the machine decides to write a new pattern of bits into it."

"Oh, so the ETC machinery actually can control this thing?" Comstock asks.

Again with the laugh. "That's the whole point! This is where the logic boards bury and disinter the data!" Waterhouse says. "I'll show you!" And before Comstock can order him not to, Waterhouse has nodded to a corporal standing at the other end of the room, wearing the protective earmuffs that are generally issued to the men who fire the very largest artillery. That corporal nods and hits a switch. Waterhouse slams his hands over his ears and grins, showing a little too much gum for Comstock's taste, and then time stops, or something, as all of those pipes come alive playing variations on the same low C.

It's all Comstock can do not to drop to his knees; he has his hands over his ears, of course, but the sound's not really coming in through his ears, it is entering his torso directly, like X-rays. Hot sonic tongs are rummaging through his viscera, beads of sweat being vibrated loose from his scalp, his nuts are hopping around like Mexican jumping beans. The crescents of mercury in all those U-tubes are shifting up and down, opening and closing the contacts, but systematically: it is not turbulent sloshing around, but a coherent progression of discrete controlled shiftings, informed by some program.

Comstock would draw his sidearm and put a bullet through Waterhouse's head, but he'd have to take one hand off one ear. Finally it stops.

"The machine just calculated the first hundred numbers in the Fibonacci sequence," Waterhouse says.

"As I understand it, this RAM is just the part where you bury and disinter the data," Comstock says, trying to master the higher harmonics in his own voice, trying to sound and act as if he saw this kind of thing daily. "If you had to give a name to the whole apparatus, what would you call it?"

"Hmmm," Waterhouse says. "Well, its basic job is to perform mathematical calculations-like a computer."

Comstock snorts. "A computer is a human being."

"Well ... this machine uses binary digits to do its computing. I suppose you could call it a digital computer."

Comstock writes it out in block letters on his legal pad: DIGITAL COMPUTER.

"Is this going to go into your report?" Waterhouse asks brightly.

Comstock almost blurts report? Thisis my report!Then a foggy memory comes back to him. Something about Azure. Something about gold mines. "Oh, yeah," he murmurs. Oh, yeah, there's a war on.He considers it. "Nah. Now that you mention it, this isn't even a footnote." He looks significantly at his pair of hand-picked math whizzes, who are gazing at the RAM like a couple of provincial Judean sheep-shearers getting their first look at the Ark of the Covenant. "We'll probably just keep these photos for the archives. You know how the military is with its archives."

Waterhouse goes into that dreadful laugh again.

"Do you have anything else to report before we adjourn?" Comstock says, desperate to silence him.

"Well, this work has given me some new ideas on information theory which you might find interesting-"

"Write them down. Send them to me."

"There's one other thing. I don't know if it is really germane here, but-"

"What is it, Waterhouse?"

"Uh, well ... it seems that I'm engaged to be married!"