In the piercing sunlight of the Big Sky country, the helicopter creates a mosquito shadow on the wheatfield and pastures on the way to Fox Trot One. We pass over farmers' silos, stuffed with the staff of life, and over the other silos, stuffed with something else altogether.

There are 1,000 of those other silos, gray-topped concrete lids covering a Minuteman intercontinental missle, spread throughout the American prairies, each missile aimed at targets in Russia. Throughout Russia, about 1,400 are aimed back at the United States. Any of them could kill a city. Most are aimed at each other in a bizaree sort of nuclear-age Mexican standoff.

Bill Andrews, 26, just married, studying for a future in the business world, is taking me by copter to his home away from home, an underground Minuteman Launch Control Facility somewhere -- the Russians, with their precise satellite photography, know exactly where -- in the outlands of Montana.

The chopper blades whump-whump-whump through Andrews' words, disjointing his Kansas drawl. He haltingly describes the feeling of having almost 10 megatons at his fingertips and probably more aimed at him.

"You just can't dwell on that kind of stuff," he says, "The magnitude, the meaning, is beyond anybody's comprehension. So we get more concerned with the technical side, taking care of the little faults in the system, running our tests, checking the communmications. There's plenty to keep us busy."

The helicopter banks, giving us a first far-off glimpse of Fox Trot, the buried nerve-center capsule that holds two missilemen and their keys to a well scattered cluster of 10 intercontinental missles armed with 800-kiloton war heads. It is one of perhaps 100 such clusters, with names like Quebec and Hotel and Charlie, divided into squadrons. The assumption in the Pentagon is that all the silos and all the Fox Trots are double-targeted by the Russians -- two warheads, in this escalated era of multiple warheads, trained on each.

Then the helicopter is swooping down toward the surface of Fox Trot One -- a few Air Force shacks enclosed by a cyclone fence, surrounded by alarm sensors that are sometimes set off by gophers and hunters. The missile-support crew is shooting baskets between two buildings they call, in this world of supertechnology, the LG and the SG -- the large garage and the small garage.

Andrews hops out first, ducking the blades, fast-pacing toward the guard standing in front of a sign that tells all in its simplicity: "Use of Deadly Force Authorized." Inside, between basketball games, the maintenance men dig up Fox Trot's gas tanks, converting them to unleaded. The guard wants two pieces of ID, just like a bank. He takes my driver's license and Visa card.

Then Andrews is standing at an elevator door, reading secret entry codes. He burns the code paper, shreds the ashes through as ashtray screen. We enter a dark-carpeted elevator, ready for the 60-foot plunge into a concrete hardened womb, secured by an eight-ton blast door.

This is the world of Ground Zero. It is a strange place in which Nudets (nuclear detonations) and SIOP (Single Integrated Operating Plan) are household terms. it is a world of super-rational men dealing with the irrational, of the super-sane dealing with insane death -- mass death, their death -- more equphemistically than funeral directors. Men, at Ground Zero, are not killed. They are rendered inoperable.

This world is a variety of places -- command posts to missile field -- from which the most dreaded war would be directed. In any "reasonable" nuclear war, or in the least irrational nuclear war, they would be destroyed in the first Russian wave. The jobs here are kamikaze jobs --and the simple sureness of it has become a way of life.

Still, being first on the target list lends itself to a gallows humor. Home is "bingo," "ten-strike" and "bulls's eye." They call it "the first goodbye."

There are many first goodbyes.

Deep inside a hollowed-out mountain near Colorado Springs, men hunched over screens and computers watch Russian submarines cruise across the Pacific until they maneuver into unseen silent "boxes" off the West Coast. They watch Soviet reconnasissance planed probe American defense perimeters in the Arctic and follow SS18 supermissiles as they are trucked across the Ukraine. This is the North American Defense Command's Combat Operations Center.

Perched on the cliffs of the same mountain is Colorado Springs' zoo. The local residents, who have lived on the edge of this for nearly two decades, have a saying: "When the animals come marching out, two by two, we'll know we're in trouble."

Inside Cheyenne Mountain, a long, black tunnel leads through chiseled rock edges, dripping with muggy moisture, to the gate of the city -- two 25-ton blast doors that look like the vault entrances at the Bank of Goliath. Behind the doors the buildings are perched on huge shock absorbers designed to cushion the buffeting from a nearby nuclear explosion. The accent is on nearby. Direct, or anything like a direct hit on Cheyenne Mountain, would be a different matter.

Bob Walden, a happy-go-lucky bomer pilot who spends a good part of his life inside the mountain, is perplexed by visitiors who find his domain surreal. He guides me through the domestic parts of his city -- an exercise room where airmen are lifting barbells to Bavarian music, a barbershop, a cafeteria where window drapes open onto blank cinderblock walls and where murals are painted to give the illusion of three-dimensional western landscapes.

Writer, Walden says, tend to get overdramatic when they wrote about his world. "Things like Red Alert are pretty Hollywood, you know."

Then we are in the command center, smaller than I had expected, looking at the lighted alert-code status board. The board shows nine states of increasing nuclear alert, with two codes for each. One code is a series of numbers -- 5-4-3-2-1 -- followed by colors, ending in Red. The other, in order, is:

Apple Jack . . .

Lemon Juice . . .

Snow Man . . .

Big Noise . . .

Cocked Pistol . . .

Fast Pace . . .

Round House . . .

Double Take . . .

Fade out.

I stare up at the codes, thinking Hollywood couldn't do much better than Big Noise and Fade Out.

"What does all that mean?"

"Can't tell you, sir. Those who need to know, know."

"Well, Cocked, Pistol means cocked pistol, cocked nuclear pistol, I guess, huh?"

"That's classified, sir."

One of the favorite stories told inside Cheyenne Mountain involves the "centerfold" episode.

About 10 times a month Russian aircraft intentionally penetrate the American defense perimeter -- an arbitrary line drawn well outside U.S. airspace.

These intrusions create a rare human confrontation. Scrambled American fighters pull in close to Russian bombers, playing car-and-mouse, being provocative at times, playful at others.

During one recent incursion of F4 pilot pulled in snugly on the rear "bay window" of a Bear reconnaissance plane, peering in for a look at the enemy. He got it --a Russian airman leering devilishly in delight as he held a Playboy centerfold almost under the American's nose.

Deep under a manicured lawn in the Omaha suburbs is the central nervous system of our nuclear arms behemoth. It is the Strategic Air Command's famous underground headquarter, the place where the red phone is supposed to be, the center from which the barrage would be sent back at the Russians, the place from -- aurhority would be transferred up to a forever flying command post plane. The plane is know as "Looking Glass," after the door through which Alice stepped into the mad world of Wonderland.

In SAC's war-gaming computers, thousands of nuclear showdown scenarios are programmed. Many allow for the survival of cities like Seattle and Kiev; some even for Washington and Moscow. Almost none foresses the survival of Omaha.

The entrance of SAC's underground headquaters is through an ordinary office building. On the right is the original red phone, encases preciously in glass. Dead ahead is a sign that says, "Peace Is Our Profession." On the left is bust of Gen. Curtis LeMay, who took SAC into the nuclear age and, politicking later as George Wallace's presidential running mate, wnated to nuke Vietnam back into the Stone Age.

After a briefing on the Russians, on missle survivability, on the aging B52 fleet, we are headed downstairs. The signs say "No Lone Zone" -- a general must be escorted. Two guards, with berets and bone-handled pistols, successively examine my coded pass.

Suddenly, I am standing on what SAC calls the Command Balcony. Then I am seated in the SAC commander's leaders swivel chair. At my right is the phone -- it is yellow, not red. Below me, my staff hunches over TV monitors. In front are my six huge viewing screens.

The lights go down to an errie, dim blue. By telephone, I get an instant weather report from Fairbanks. They flash a map of isolated radar posts, ask who I want to talk to. I hurriedly choose two remote Arctic stations. Cracking through the void comes a Midwesern drawl from an island far out in the Aleutians, then a heavy, friendly French-canadian accent from north of Hudson's Bay. screens, rapidly. The lights flash under the clocks marked Omaha. Zulu, Washington and Moscow. They flash past the 11-man staff below me. Everyone stops. Flashing red lights, screaming silently through the netherworld blue, command quiet for an important incoming message.

And then we are talking to the Looking Glass Plane, that strange airborne command post flown SAC's finest, a pilot with one black eyepatch. The eyepatch is functional, not macho, although the pilot has perfect vision. would take the patch off the good eye, put it over the bad eye, and fly on.

The voice comes down, clear and monotone, like a routine crowd-pleaser from an airline captain: "We are flying somewhere over the central United States at an altitude of 26,000 feet . . . "

The Looking Glass plane is always there, refueled by tankers. It comes down when the engines run low on oil, because it can't get a midair oil transfusion. Another goes up to replace it before it lands. The planes are jammed with electronic and communications gear to carry on a war if there is no way to carry it on from the ground.

The Looking Glass plane always carries at least one SAC general. They would attempt to get the president aboard in a war, if they could figure out who was then president and if they could find him and if they could land.

At Fox Trot One the elevator descends slowly, as if into a tomb. In all his experience, my guide Bill Andrews says cheerfully, the elevator has malfunctioned only once or twice -- "pretty good for a machine."

Ahead of us in a 6-by-12 cubicle are two young men, decked out in the missilemen's stark blue uniforms and dashing red ascots, surrounded by all their machinery.

The green strategic alert light is on. So are a lot of missile-launch panel lights, marked with crayon to show they, not the missile system itself, are malfuntioning. The launch code affirmation machine, which would confirm a presidential war order, looms above. It has 16 million combinations. "You could play with it for 10 years and never beat it," Andrews says.

Then he introduces me to the commander. Brad Butler, and his No. 2, Harry Minniear. Butler is round-faced and 25; Minniear is baby-faced and 23. Behind them, on a little TV screen that brings in commerical shows, the Muppets are playing.

Butler and Minniear are down here on a 24-hour stint, Andrews just off his but returning as a tour guide. They go 24 hours on, 48 hours off. They do this for three years. Most of them are studying for advanced college degrees.

Tomes have been written about the psychology of missilemen like Butler and Minniear. Could one man beat the system, launch without orders? What would happen if one of them cracked up? Both cracked up? Minniear, at age 23 has more warpower at his fingertips than Alexander, yattila, Genghis Khan, Napoleon and Hitler combined. One turn of his key could take out 10 cities.

But there are two keys, locked in red boxes 12 feet apart. Each missileman has his own lock combination. Before one facility launches, it must have a confirmation of the order from another, buried miles away. Simultaneous turn of the two keys would be required to launch missiles. Just in case, each of the missilemen in each launch capsule has a sidearm. If one should go mad, the other would shoot him. Such are the safety procedures.

Still some have doubts. One author has described a "spoon and strong" system supposedly worked out by a Minuteman crew. In this theory, one man could launch. He would tie one end of a 12-foot string to his partner's key, turn it by twisting a spoon tied to the other end.

"It wouldn't work," Butler says. "You do a lot of fantasizing down here at night after 15 or 20 hours."

I glance at Brad Butler's pistol and ask if he could use it on Harry Minniear. He looks at his young partner, sheepishly. Minniear stares back, wisp of a smile.

"Look," Butler says, "I know people worry about it, but one of us couldn't launch, no matter how hard he tried. First I would have to break the launch code, then I have to get Minniear's key and only he has the lock combination, then I have to break the war-order code -- a 1-in-16-million shot -- and then my launch order has to be confirmed by another crew 50 miles away. There is just no way."

The capsule is a babble of buzzers, bells, rings and whirrs -- most of them communications checks with the outside. The conversation move away from madman theories onto being targeted, prime-targeted, and onto targeting others.

Butler has been down here 20 months, Minniear seven. Being in the crosshairs of Russian megatons leaves them almost hauntingly nonchalant.

"I don't even concern myself with that," says Butler, "I'm a business major and this is just my job."

"It would be much spookier to be the marine lead man on a beach landing," adds Minniear.

"Given that choice," Andrews cuts in, "I'd rather be 60 feet underground." He is more worried about his new wife, Jill, above ground. She is a Minuteman security cop, and drunken hunters sometimes take potshots at the security patrols.

The conversation switches almost automatically to the awesome responsibility, moral and otherwise, of having the keys to perhaps 10 million lives. Butler and Minniear would never known their targets -- perhaps cities, perhaps air bases or missile capsules like thier a half-world away. But they would turn the keys.

One night, Andrews recalls, the phone range on Fox Trot One's only outside line to the real world. After answering, "Minuteman Launch Control Center," he listened silently while the caller gave him a full order for pizza. With pepperoni. It went undelivered. Another kind of order would not.