"Why not? I mean, you're talking about three measly letters. Like those monkeys typing King Lear."

"For your information, a three-letter code will yield 17,576 possible letter combinations in the English language alphabet. The Russian alphabet, with thirty-three letters, will yield 35,937 different codes." He explained, "Thirty-three, times thirty-three, times thirty-three equals 35,937. So, what are the chances that a naval radio operator could mistakenly send the code to the submarine fleet to launch their missiles at their predesignated targets?"

Considering the fact that if something could go wrong, it would, I thought the chances seemed pretty good. I said, "Maybe we should use the Russian alphabet. You know? More letters. Less chance of starting a nuclear war by accident."

He found that funny and said to me, "Actually, if you want to know more than you need to know, whoever transmits the message needs to send it as a repeating, error-correcting code, followed by another three-letter verification code. No one can screw that up by accident."

I asked the obvious and more pertinent question, "How about on purpose? Like some nut who wants to start an atomic war?"

He thought about that and replied, "As I said, the codes change frequently."

"But if someone had the code-"

"I can't imagine that any unauthorized person could get the initiating codes and the verification codes, plus getting the current encrypting protocols. Also, the computer encryption software is sophisticated beyond anything you can imagine." He added, "You shouldn't worry about things like that."

I thought of Bain Madox and wanted to say to Commander Nasseff, "You should."

Kate asked, "And there is no other possible application for this means of communication? I mean, no other use for ELF waves other than military?"

"Well, that was true. But I've heard that since the end of the Cold War, the Russian ELF transmitter has been used for geophysical research. Swords into plowshares." He explained, "The ELF waves can penetrate deep into the Earth's crust and can therefore be used for electromagnetic sounding and monitoring. For instance, seismic research. Earthquake predictions and things of that sort. But I don't know much about that."

Kate said, "So, theoretically, someone outside the military could send an ELF transmission. Like scientists."

"Theoretically, but there are only three ELF transmitters in the whole world, and they're all owned by the military." He added, "We have two, they have the other."

Kate thought about that, then asked, "I see ... but theoretically ... is this top secret, or is it unlawful to build such a transmitter?"

"I don't know about unlawful, and there's nothing top secret about the technology or the physics behind it. The actual problem is that an ELF transmitting station can be expensive to build, and it has no practical application outside of contacting submarines or, recently, in limited geophysical research."

I didn't think that Bain Madox was interested in geophysical research, but he might be, so I asked, "Can these ELF waves detect oil deposits?"

"I would think so."

"So, geologists could use them to find oil."

"Theoretically, but ELF stations can only be built in a few places in the world."

Kate inquired, "Why is that?"

"Well, now that we're talking about the actual transmitter itself, let me explain that. You asked why a submarine can't send an ELF message. One reason is that an ELF transmitter can only be located on land in an area that has very low ground conductivity. And there are only a few places on the planet where this geological condition exists."

I asked, of course, "And where is that?"

"Well, one is where the Russian transmitter, called Zevs, is located-northwest of Murmansk, up near the Arctic Circle. Another place where these necessary conditions exist is here in the U.S. Our two transmitters are the Wisconsin Transmitter Facility-WTF-and the Michigan Transmitter Facility-MTF, and they both share the same geological formation called the Laurentian Shield."

"And that's it?"

"Well, that's it for existing ELF transmitters. But the Brits almost built one during the Cold War for the Royal Navy at a suitable location called Glengarry Forest in Scotland. But for a variety of political and practical reasons, the idea was scrapped."

Neither Kate nor I said anything for a while, then Kate recapped, "So, there are only three ELF transmitters in the entire world."

Commander Nasseff made a little joke and replied, "Last time I counted."

Well, I thought, count again, Commander.

Kate and I glanced at each other, but neither of us asked the obvious question about other suitable and perhaps close-by locations. We knew we needed to finesse that question so as not to have Commander Nasseff sitting around the coffee bar telling people that Corey and Mayfield were asking about ELF transmitters in the Adirondack Mountains.

John Nasseff took the silence to mean we were done taking up his time and asked, "Was that helpful?"

Kate replied, "Very. Thank you. One more question. I'm not clear on something. You are saying it's possible for a private individual to build an ELF transmitter?"

John Nasseff was probably thinking about lunch, but answered, "Sure. Someone can build one in his basement or garage. It's actually fairly basic technology, and some of the components are probably off-the-shelf items, and what's not readily available can be built or bought for the right money. The real problem is the location of the antenna and the size of the antenna."

"Why is that a problem?"

"Because, this is not a standard vertical antenna. An ELF antenna is actually a long cable, or cables. These cables are strung on telephone-type poles, usually in a big circle, and they run for miles."

That sounded like something I'd seen recently. I asked, "Why is that difficult ... or expensive?"

"Well, it's expensive," Nasseff replied, "if the government does it." He got off a good laugh, then continued, "As I said, it's all about geology and geography. First, you need to find a location where the rock formation is suitable, then you need to acquire a sufficiently large area of that land."

"Then what?"

"Well, then you string your cables, which are actually the feed for your antenna. These cables may have to run for hundreds of miles-in a circle to save space-or, if the geological conditions are perfect, you could get away with, say, fifty miles or less."

Kate said, "I'm not quite following the geological angle."

"Oh, well ... let me look this up ... okay-a necessary ground condition to build an ELF antenna is an area where there are only a few meters of sand, or moraine gravel. Beneath that, you need a rock base of igneous granite, or metamorphic ... what the hell is this?" He spelled, "G-N-E-I-S-S."

I said, "I hope that's not the code to launch."

He chuckled. "I guess it's a type of rock. Let's see ... areas of very old Precambrian mountain chains, such as the Laurentian Shield, where our ELF installations are located ... the Kola Peninsula in Russia, where they have their ELF installation ... this place in Scotland where the Brits decided not to build an ELF station ... a place near the Baltic Sea ... well, you get the picture."

I didn't hear him say, "The Adirondack Mountains," and I was really listening closely.

He continued, "So, if someone wants to build an ELF station, he goes to one of these areas, buys enough land, then sinks telephone poles in the bedrock and strings antenna wire between them, in a circle. The better the geological conditions, the shorter the wire has to be to provide the same transmitting power. Then the antenna wire is connected to a thick copper grounding cable, which runs down one or more of the telephone poles into a deep borehole in the low-conductivity rock. Then, a powerful electrical generator-and this is a big expense-feeds the antenna cables, and the current runs around the antenna wire, then goes down the copper grounding cables into the rock. And then, the Earth itself becomes the actual antenna. Follow?"

I replied, "Absolutely."

I don't think he believed me and he said, "This is a little technical for me, too. But it seems that if you have enough electrical generating capacity-thousands of kilowatts-and once you get the antenna right, the actual radio transmitter is not that difficult to build, and you can transmit ELF wave signals to your heart's content." He added, "Unfortunately, no one is listening."

I reminded him, "The submarines are listening."

"Only if they happen to be on the frequency that you're transmitting. The Russians are transmitting on 82 herz, and we are transmitting on 76 herz. And even if the submarines are hearing something on the appropriate frequency, their ELF receiver would probably reject the signal."

"Why?"

"Because, as I said, military signals are computer encrypted. Encrypted when transmitted, and decrypted at the receiving end. Otherwise," he explained, "any nut-as you seem to be suggesting-could theoretically play havoc with the Russian and American nuclear submarine fleets. You know, like start World War III."