Seven F-15 Strike Eagles flew in a diamond wedge formation over eastern Colorado. They departed Buckley Airforce Base in Aurora where they had been temporarily stationed. They headed due east towards the Kansas border, and their intended target. Each was armed with eight AMRAAM medium range air-to-air missiles, modified to deliver fragmentation warheads, and a Phoenix long range air-to-air missile, as well as their standard 20 mm gatling guns.

  Approximately fifteen minutes behind them followed a single A-6 Intruder attack aircraft. It carried a single Tomahawk Land Attack Missile under its fuselage with a special warhead. The pilot was Lt. Col. Eile Chica. Her squadron, which included the Eagles, had been transferred from California a week before just for that mission. Their target was the Walker, which was on a direct course for Denver, and if not stopped would arrive in twelve hours. Wherever it went, it left nothing in its wake.

  Eile's mind wandered as she zoned out the monotonous task of straight, level flight. She recalled the briefing she and her people had been given when they first arrived. Approximately nine months ago, a meteorite crashed into the ocean a couple of miles off the eastern seaboard of the United States. Though it had been a large one and had caused some flooding along the Atlantic coast, the public quickly forgot it.

  Six months later, the Walker came ashore off New York City. Though it gleamed as if made of metal or plastic, it had a smooth, organic shape, with no obvious seams or joints. It consisted of a bulbous, misshapen body, like a russet potato, with numerous feathered and branched appendages. It stood and walked on three spindly legs. The surface of the body appeared featureless except for what looked like a single, blood-red eye covering about one-sixth of the surface area. Except that instead of being used for seeing, it fired a disintegrator beam that could reduce anything to plasma in an instant. It destroyed everything in its path, leaving nothing but bare rock and a layer of dust.

  The devastation caught everyone by surprise. All attempts to communicate with it went unanswered, though whether it simply ignored them or could not understand them no one knew. It travelled in a straight line, cutting a swath through the heart of the city twenty miles wide. The military responded immediately, but few weapons could get past its formidable defenses. Of those that did, most were destroyed by the disintegrator beam. The rest either couldn't penetrate the skin or only damaged the appendages, which grew back in a very short time. One aircraft that made a kamikaze run did succeed in damaging the body, but it too quickly regenerated.

  From New York it continued cross-country, devastating Pittsburgh, Columbus, Indianapolis, St. Louis, and everything in between. Outside of Kansas City, the President authorized the use of nuclear weapons. He had been reluctant, for fear of civilian casualties, but he finally decided he had no choice; nothing else seemed to work. A cruise missile carrying a one megaton warhead detonated a mile above the Walker, well out of reach of its defenses. The shockwave smashed it into the ground, and the heat bloom seared and melted it. It seemed to be finished, and a research team was assembled to study whatever might be left. It took them a day to arrive, and they found the Walker not only intact, but nearly operational. It annihilated the team and destroyed Kansas City before continuing on towards Denver. The town of Hays had been wiped out just the day before.

  The radio crackled. "Flight leader, Eagle flight, we have visual contact with target. ETA now fifteen minutes."

  "Eagle flight, flight leader, we copy," Eile replied. She glanced at her navigator-bombardier. Maj. Sonne Hiver nodded back. "Confirm fifteen minute ETA. You are cleared to arm. I repeat, you are cleared to arm."

  "Wilco, flight leader. Eagle flight out."

  "Almost there," Eile remarked.

  Maj. Hiver, whose callsign was Sunny, nodded again. "Ten beers says we won't get the bastard until after the first run."

  Eile grinned, though Sunny couldn't see it as it was hidden by her flight mask. "Yer on, sucker."

  Sunny giggled. Eile reflected, not for the first time, how odd she acted. Surprisingly silly and girly for a serving Air Force officer, she was nonetheless the best navigator in the service. She had been transferred to Eile's squadron just a year before, and she proved her worth on her first mission. Eile assigned her to her own Intruder because she wanted the best by her side. She had an almost intuitive grasp of navigation, and could calculate even complex targeting equations in her head. Since she joined the team, the squadron's mission success rate had jumped a hundred and fifty percent.

  Now she needed her even more than ever. The consensus among the think tank eggheads was that the Walker was a berserker, a machine designed to kill and destroy. They speculated that it had been developed either as a doomsday weapon or as a way to eliminate possible interstellar threats and potential competition. They couldn't say whether its appearance had been a random landing or a targeted strike, but they estimated that just one Walker could clear the continents of all human life in a year.

  Fortunately, there was hope. A salvage mission by the Navy managed to recover material from the ocean floor that they believed came from the Walker after it crash-landed. That had been confirmed by comparing it to material recovered from the nuclear detonation site. Analysis of the material revealed that its structure was built and maintained by nanotech robots no bigger than bacteria, which explained how it could repair itself even after being blasted by a nuclear bomb. Somehow, a group of scientists managed to reprogram a collection of nanobots to demolish the Walker's substance rather than rebuild it. Those had been packed into a warhead installed in the Tomahawk. Everyone hoped that when the missile struck, the nanobots would be released on impact and would destroy it. It was a gamble; no one knew if it would work, or how long it would take, though the concept had been proven using the recovered material. But gamble or not, it was their best hope. If it failed, their only remaining option would be to try to make a direct hit with a ten megaton bomb, but there were those who didn't believe it would work.

  The radio broke into Eile's thoughts. "Flight leader, Eagle flight, ETA five minutes."

  "Eagle flight, flight leader, roger, cleared to engage, repeat, cleared to engage."

  "Wilco, flight leader. Out."

  "They're getting into position," Sunny reported.

  Eile couldn't see it, they were still too far away, but she imagined the Eagles breaking formation to reassemble into a vertical rosette. Six planes would form a ring around the seventh, creating a large face from which to fire a massed salvo to break through the Walker's defenses.

  It had only a two-layer barrier, but it was formidable. The first layer consisted of a field of aerial mines called Poppers. About the size of a softball, they floated in a torus around the Walker. Though only one Popper occupied a cubic meter, the field consisted of multiple staggered layers that closed all gaps. They exploded on contact, but the thickness of the field ensured that even a missile trying to penetrate would probably hit at least one, and no aircraft had ever made it through unscathed. Despite their size, they packed a wallop; just one could destroy a fighter, and three or four could bring down a bomber.

  Experience had shown that only when enough Poppers had been destroyed could aircraft get through the field; the magic number seemed to be eighty-five percent. Military analysts had also discovered that it wouldn't be necessary to attack the whole field. Once a Popper had been put into place, it stayed in its place until destroyed. Hence, if a section of the field could be reduced to 15% intact or less, aircraft could make it through. The vertical rosette had been designed to accomplish this. When they got close enough, the Eagles would fire their fragmentary AMRAAMs, and with any luck they would blow a hole through the field.

  After that came the second layer, a ring of satellites each the size of a weather balloon. If anything got past the Poppers, they would emit an electromagnetic pulse that would fry all semi-conductor circuits in range, effectively disabling any electrical and computer system. The Eagles had been specifically hardened against the EMP. Hopefully they would
survive long enough to take out the nearest satellites with their Phoenixes. That would clear the way for the Intruder to make its bombing run against the Walker.

  But regardless of the success of the mission, the Eagles were not expected to survive. Eile had made participation in the mission strictly voluntary, but she had been made proud when all her pilots volunteered. Those that accompanied her had been chosen by lots, except their leader.

  "Flight leader, Eagle flight, in position, standing by. Three minutes to contact."

  "Eagle flight, flight leader, roger."

  "Flight leader, target acquired. Pickles going hot. Two minutes to contact."

  "Eagle flight, copy. Fire at will, repeat, fire at will."

  "Wilco, flight leader. Ninety seconds to contact. Fox three."

  "First salvo away," Sunny reported.

  Eile waited anxiously for the results.

  "Popper field 98% intact," Sunny reported.

  "Flight leader, sixty seconds to contact, fox three."

  "Second salvo away." Pause. "Popper field 95% intact."

  "Shit, this isn't working! Eagle flight, fire all missiles, repeat, fire all missiles."

  "Copy, flight leader, wilco. Thirty seconds to contact, fox three."

  "Third salvo away."

  "Come on, come on!" Eile muttered.

  "Popper field 90% intact," Sunny squealed, anxious.

  "Dammit! Break off, Eagle flight, break off!"

  "Negative, flight leader, we still have our cannons. We'll get you through. Five seconds to contact. Eagle flight out."

  "They're going in!" Sunny yelped.

  "Aw, cripes!"

  "Eagle three, gone. Eagle five, gone. Popper field, 88%. Eagle six, Eagle two, gone. Popper field 85%. Eagle four gone, Eagle seven gone, Popper field 83%."

  "Eagle one, break off! That's an order, break--"

  "It's too late!"

  Eile saw a small fireball bloom in the distance.

  At first too shocked to speak, she soon felt rage boil up inside her. "Dammit, dammit, dammit!" She knew the odds of Eagle survival would be low, but it seemed so senseless for them to throw away their lives like that. They were good men and women, most with families. For a moment, she hoped she wouldn't survive, so she wouldn't have to inform their loved ones.

  "Status," she ordered. When Sunny didn't reply, she turned to look. Sunny stared out the window as if stupefied.

  "Major!"

  Sunny jumped and looked at her.

  "Status!"

  Sunny looked at her instruments. "Popper field 80% intact."

  Not enough; nowhere near enough, Eile thought. "Jesus, we're not gonna make it." And she didn't know what hurt most, that they would fail their mission, or that Denver would be wiped out.

  "Uhm, Eile?" Sunny said in a hesitant voice. She could hear it tremble.

  "Yeah?" She ignored the informality; it was not the time for protocol.

  "There's something I've been wanting to tell you for some time now."

  "Yeah?"

  "I don't know if this is the right time, but--"

  The radio came to life as a western twang bellowed forth. "Hey there, little ladies! You all need some help?" A camouflaged A-10 Thunderbolt II passed over their top from one side and slid in front of them.

  "Cowboy!" Sunny squealed in relieved delight.

  Eile swore under her breath. "Oh, great, that's all we need."

  "Yo, Miss Eile--"

  "That's Colonel Eile, Captain."

  "Right you are, Colonel. Have I ever told you you look prettier than a heifer in clover?"

  "Only about fifty times in the past two days!" Sunny replied.

  "Sunnyyy, Jesus!"

  "You got that right, Miss Sunny."

  "Major Sunny, if you please."

  "Dammit, Cowboy! I told you to stay back at the base. That warthog's too slow to keep up."

  "Not any more! I suped this Old Gal up. She kin now fly rings around your tail, Missy."

  Sunny giggled.

  "You leave my tail out of this, buster."

  "I'd sure like to, Colonel, but this here mission's much too important. We gotta wax that Walker before it reaches Denver, or millions are gonna die."

  "Tell me somethin' I don't know."

  "Alright. I kin blast you a hole through them Poppers and give you a fightin' chance of puttin' your payload right smack on top o' that Bad Boy. How's that?"

  "And what makes you think you can do it when a whole flight of Eagles couldn't?"

  "Oh, I don't know. Maybe 'cause I'm the best? Besides, all they had were some firecrackers and popguns. I got me a thirty mil gatler, along with eleven heavy-duty HARMs. But I tell you what. Let's sweeten this rhubarb. If I get my ass shot off, you kin have my whiskey ration for the rest o' the year, but if I get you gals through, you gotta go on a date with me, Colonel. Whaddya say?"

  "What?!"

  "Hey, fair's fair. I've been tryin' ta get a date with you ever since I first laid eyes on you. This is my big break."

  "If I order you to escort us, you'd have to do it, date or no date."

  "That's true, but then I wouldn't have the incentive ta do my best, now would I?"

  "Dammit, Cowboy--"

  "Whatever you're gonna decide, do it fast!" Sunny admonished. "We reach the field in five minutes."

  "Aw, cripes! Alright, Cowboy, it's a deal."

  "Well, butter my biscuits, Momma! You gals hug me tight and match my moves, and I'll plow the road for ya! YEE-HAW!!"

  Eile saw the 30 mm Avenger gatling cannon under the Thunderbolt's nose begin spinning, and immediately after that it spat fire as it discharged its rounds. Moments later, Eile saw tiny fireballs flare up ahead of them.

  "Popper field 75% intact; check, 70%. No, 65%. Now 60%! It's working!"

  "Well, I'll be damned!"

  "Fifty percent!"

  "Hell, Cowboy, what're you shooting?"

  "Forty percent!"

  "I had my ground crew load me up with incendiaries."

  "Thirty! That's gotta be it! The Poppers must be heat sensitive. Twenty-five!"

  As Sunny continued the countdown, Eile felt in conflict. On the one hand, she wanted their mission to succeed, but on the other, she didn't want to keep her date with Cowboy; the very thought filled her with dread, though she wasn't sure why. Yes, he was a brash loudmouth with the manners of a country hog, but he was also handsome, and chivalrous in his own way. She just didn't like him, and she didn't want to encourage him.

  "He did it!" Sunny's squeal of triumph broke through her thoughts. "Popper field only 5% intact. Thirty seconds to contact."

  "What did I tell you? Now, you gals follow me. It'll be tight, but I'll take you through slicker than a mustered-up hotdog down my throat."

  "That'll do, Captain!"

  "Right you are, Colonel! Try ta keep up! YAH-HOO!"

  The Thunderbolt jumped ahead. "My word!" Sunny said.

  Eile just shook her head as she took the stick and pushed the throttle forward. "I'm shutting off the autopilot." She felt herself pushed back into her seat as the Intruder accelerated, closing the gap with the Thunderbolt.

  "Fifteen seconds to contact." They had come close enough to see the field. Though individual Poppers were still indistinguishable, the field itself looked like a powdered donut, but with a hole bored into it in one place.

  "Cowboy, you ride shotgun. I don't want any surprise visitors while we're in the field."

  "You got that right, Colonel."

  "Five seconds to contact!" The field began to break up as the Poppers became visible. The hole turned into a tunnel, and Eile could see through it to the other side.

  "Here we go. You gals hold onto each other real tight, now. It's bound ta get bumpy!"

  "Ah, sheesh."

  "YIPPEE-KI-YAY!" The Poppers flew past the cockpit as the two planes roared into the tunnel. Inside the field Eile found her view obscured after a short distance in any direction as the other Poppers further away crowded i
n closer together. It seemed like flying through a cloud, except it was lighter than she expected. Probably because the Poppers reflected the sunlight all around.

  "Radar's out," Sunny reported; "avionics scrambled."

  "Roger." That had been expected. The field used some kind of electromagnetic force to hold the Poppers in place, and it wrecked havoc with aircraft electronics, but it would clear as soon as they left the field, all except the radar. The Walker jammed that.

  Cowboy's gun flared and an explosion burst a hundred feet in front of his nose. "Got one!"

  "A little warning next time, Captain."

  "Right you are, Colonel." His gun flared again, and another Popper exploded in their path. "Got another one!"

  "Dammit, Cowboy--"

  "Lift yer skirts, gals!"

  "Popper, four o'clock low!" Sunny said.

  Eile pulled back on the throttle and stick, backing the Intruder off and nosing it up as a Popper streaked by beneath them.

  Cowboy fired again. "Heads up, ladies!"

  Eile saw another Popper coming in over the top of the Thunderbolt. She nosed down and it just barely missed grazing the canopy.

  Cowboy fired a third time. Another explosion, just ten yards ahead, lit up the sky.

  "Gall dang it! Two slipped through. Watch yet feet!"

  Eile banked left to avoid the closer one, then slammed back to the right. She heard a hiss as the Popper grazed the underside of the Intruder's fuselage, then the fighter bucked from an explosion behind.

  "Status!"

  "I--I can't tell, not until we clear the field!"

  "Cripes!" Still, the plane seemed to handle okay and there had been no alarms. "Maybe we got lucky."

  Suddenly the sky cleared. Looking around, Eile saw they had emerged into the open.

  "We're through!" Sunny said. "Avionics stabilizing. Minor damage to tail assembly and rear fuselage. Radar still out."

  "You ladies get yer tails singed?"

  "Never mind our tails, Cowboy! Still, good work."

  "Hey, thanks Colonel! Comin' from you, that just warms my heart."

  "Ah, sheesh."

  "Two minutes to String of Pearls." Ahead, Eile could see a ring of featureless, smooth, pearly white balls. Inside, at the center, she could just make out the Walker. A blinding blue-white beam lanced out from its nose, striking the ground some distance in front of it, followed by a flash and a glowing cloud that rose into the air. It dissipated almost immediately, leaving a haze of suspended dust.

  "Okay, Cowboy, you've done yer bit. Hit the deck, we can take it from here."

  "I know you kin, ladies, but if it's all the same to you, I'd like ta stick around and see how this turkey-shoot ends."

  "That's an order, Captain!"

  "Well, now, I appreciate that, and I ain't never disobeyed orders before, but it seems ta me you could still use my help."

  "We can manage just fine without you."

  "Right you are, Colonel, but I've got an incentive ta keep you alive, or are you tryin' ta welsh on our bet?"

  "Dammit, Cowboy--"

  "I'm reading an EMP build-up in the nearest Pearls," Sunny reported. "They're getting ready to fire!"

  "I hate ta interrupt, but I'm gonna be busy here fer a few minutes. Tell you what, you can court-martial my ass after our date, how's that?"

  "He's locked on with his HARMs!"

  "Aw, cripes! Consider yourself on