Five by five, Assault. We are holding onto a golf course approximately one quarter kilometer north and east of your location, taking heavy fire... scratch that, not fire, you know what I mean. We've got air support coming in from Buckley ANG to remove friendlies, can you assist?

On our way, Stryker group, comms said, but they were already in the middle of it. The HEMTT crept forward into a leafy residential street and grumbled to a stop. Ten or so infected stood in the intersection, stumbling on ravaged legs. One of them turned to look directly at Clark through the windshield. He heard Horrocks shouting at Squad Two and the infected man's head erupted like a volcano. An infected woman in a bright red sweater came hurrying toward the truck, her long black hair floating behind her, still silky and full of body even though her face was grey and pitted with sores. The squad cut her down, too-and an old man in a pair of coveralls, and a teenaged boy wearing a sweatshirt. There were more of them and more coming down the street, perhaps drawn by the combat noise.

Chief, we need to get through here, Clark yelled out the window. Th e sergeant was on it, shouting for his platoon to deploy themselves in a semicircular formation before the truck. Clark addressed the HEMTT's driver. Specialist, take us in as slow as you can-let these men do their work without having to be afraid of getting run over.

Inch by inch they pressed forward. The troops took their time, lined up their shots. There seemed to be no end of infected citizens for them to mow down but they had a sizeable advantage-they could think, for one thing, rather than just running blindly into a crossfire. They had the advantage of being able to strike from a distance. They had their training and discipline to fall back on.

Stryker group, we are converging on your location but meeting heavy resistance, comms said, holding her phone tight against her face. A bloody hand smacked against the window beside her face and she screamed. Clark drew his sidearm but the squads had already pulled the infected man off of the side of the truck and blown open his skull.

Out of the cab, beyond Clark's line of sight someone let loose with a sustained burst of automatic weapons fire-a pointless waste of ammunition and a sign that somebody had lost his or her cool. Clark climbed over the comms specialist and jumped down to the street to see what was happening. Infected crowded around on every side, more of them coming out of every side street, every alley, every garage and doorway. Clark loosed his weapon and shot down a bald man with no skin on the lower half of his face.

For a moment nothing was moving, no one was firing. Clark's mind immediately leapt to the pertinent question: why?

Why was he here, what did he hope to accomplish? He was wasting his time, achieving nothing. The blonde girl with the tattoo could be anywhere by now, he thought, shecould have slipped through his grasp already. Certainly he'd heard nothing from the Marine roadblock at Twenty-nine Palms.

Motion on the edge of his vision startled him back to focus. More of them -how? How had the pathogen spread so quickly? Clark was sick of asking himself that question but he was constantly confronted with new variations on the theme. How did this start? What enemy, what nation, what terrorist faction would let this happen? He fired again and a naked woman spun off her feet and landed in a heap. He lined up his next shot and pierced her cranium.

He was putting them out of misery, he told himself. Yes, they were sick people. Yes, they were citizens of the United States. But if the pathogen spread this quickly there just weren't enough doctors to treat them all. Especially since half the doctors in the country were probably already infected themselves.

He had his orders, but never in his life had that been enough. He'd always wanted to know how things worked, and why.

Chief, do you think we can just ram through this? he asked, his voice low. He was allowed to ask his sergeant questions but it was better if the troops didn't hear.

Horrocks spat noisily. They'll get stuck in the wheels. We'll get bogged down and eventually we'll run out of ammo, sir. I was afraid you'd say that. Open me up an escape corridor. We need to reinforce that Stryker group. Get the men on the truck, the, the men and the women. He wasn't fresh. That was all. Normally he would never have made such a mistake but he had been too long without sleep or real food. Get the troops onboard, and clear me a path with the SAW, with the small arms, whatever we have.

Sir, yes, sir! Horrocks shouted and made it happen. The SAW crew on the roof of the HEMTT opened up with an unholy rattle and the infected fell before the truck like corn at the harvest. The troops clinging to the sides and top of the vehicle slaughtered anything that tried to get into the gap the SAW made. The driver got them moving, both arms clutched around the steering wheel as the HEMTT drove up and over the pile of bodies and they popped through the crowd like a cork out of a champagne bottle. In under sixty seconds they were spinning out on a perfectly manicured golf course, fighting to keep traction.

The infected came at them from behind but Squad Three kept them at a distance with harassing fire. On the grass the driver opened up his throttle and they raced over and through bunkers and greens. Clark could see the Strykers up ahead. He counted three vehicles. There should have been five. One of the light urban warfare tanks looked badly damaged as well. They had been parked in a triangular formation that allowed the group to cover enemy action from any angle. The golf course around the armored vehicles was pockmarked with dark, smoking craters and Clark saw civilians, perhaps seventy-five of them and many badly wounded, huddled inside the loose perimeter. Added to the shell-shocked survivors in the back of the HEMTT that made nearly a hundred.

There had been two and a half million people in Denver, once. One of the Strykers deployed a spread of grenades from a roof-mounted MK-19 and smoke and fire tore through a stand of trees, shattering the wood and sending clouds of leaves twirling down through the air. As they pulled up to the Stryker group Clark heard the vehicles' .50 caliber machine guns roaring in tight, controlled bursts, chopping down clusters of the infected as they emerged from the surrounding streets and buildings.

The comms specialist's phone chimed and she answered it, Copy that Buckley, we are five by five. Captain, sir, there's a helicopter coming in right now to upload these friendlies and they can take ours, too.

Alright, finally, Clark said. Finally something would actually be finished. H e squinted against the sun and saw an MH-53 Pave Low coming in just above the tree tops. At least something was going right. The Pave Low, a double-wide chopper studded with instrument and weapon pods, was the biggest rotor-wing aircraft the ANG possessed. It could carry the most survivors.

The Pave Low dropped its ungainly bulk onto a putting green and started loading civilians onboard. A copilot wearing a gold Second Lieutenant's bar dropped out of the crew hatch by the nose and came running up to throw Clark a salute.

I admire your timing, airman, Clark said, returning the salute. We just arrived here ourselves.

Sir, permission to inquire whether I am addressing Captain Bannerman Clark, sir?

Granted, and yes, you are. What's going on? Speak candidly, son, I don't have all day. Sir, I have special orders for you, sir, straight from the Pentagon. The Civilian, Clark thought. The man with the marshmallow peeps. What was he thinking, issuing orders to a military unit during combat operations? We're supposed to track you down and send you home. You should take your platoon and head somewhere fortified, they told us. Hunker down and wait for further instructions.

Clark sputtered in surprise. That's preposterous. There's still work to be done here and I'm not leaving until that work is done and it isn't done until I say when it is done! Guilt, he thought. He was feeling guilty for his earlier doubts.

The Second Louey looked down at his flight boots. Sir, begging your pardon but I'm just the messengerand... sir, I've been flying over this town back and forth all day. I'm truly sorry but when you say there's work to be done-there's not. We haven't seen any sign of real survival since this morning.

Ice cubes trickled down Clark's spine. That's, he said softly. That's not the kind of attitude I like to hear, he continued but he couldn't finish the rebuke. He tried to remember when the last survivor had climbed aboard the HEMTT. The last time they'd seen anyone else opposing the infected.

He took a second to think about what that meant, but only a second.

Sergeant Horrocks, he called, did you hear what this man had to say? It's time for us to make a tactical withdrawal.

Formerly known as a retreat. The National Guard-and the Federal Government-had written Denver off.

Get your asses in gear, my little babies, Horrocks screamed at his platoon, walking away. We're popping smoke! At the news some of the troops offered up a weary cheer.

Dear Sis: The elms outside my window are dying, which hardly seems like a big deal now, does it? And yet I cant help but look at them, at the sickly leaves and the branches that just arent budding. Someone came by today to paint them with medicine but stopped before he was half done, everyone is so distracted right now. Heard San Francisco was gone, now how could that be? How do you lose an entire city?

The nurses turned off the television before I could find out. Please visit soon, if you can.

Love, Irene

[Letter delivered to an abandoned apartment in Minneapolis, MN 4/8/05] The tiny house stood on short stilts above the floor of the box canyon. A narrow row of stairs lead up to a weathered wooden door that didn't quite fit its frame. Behind the house stood a white cylindrical tank, probably the fuel supply for a generator or a gas stove. Nilla spent most of an hour checking the place out, climbing the rocks all around. No road, not even a path lead to the misshapen door. As far as she could see in every direction lay nothing but desert. Who would live in such a desolate spot?

She was asking herself that question when the door swung open, revealing a rectangle of cool darkness beyond. Unable to move fast enough to find cover Nilla did what was starting to come natural-she hid away her energy, made herself invisible.

A man stepped out of the house and onto the first of the steps. He wore nothing but a pair of boxer shorts and a white beard that descended in bushy curls to the middle of his chest. His head was shaven, or perhaps just bald. His skin had the sallow shade of undyed leather and he looked like he might be a hundred years old or perhaps only sixty. He scratched the back of one thigh and stared right at Nilla. That's pretty good, he said. Please, come inside. We need to talk.

"I heard a guy on the tv today, I think he was an evangelist or something."

"Yeah."

"He was talking about the end of the world. Saying-"

"Yeah." "- right, saying maybe this, you know. Maybe this is it. Judgment day? And were being punished because of our sins. And that got me tothinking..."

"Yeah?" "Well I mean if weve already been judged, right? If God has already decided whos good and whos bad and all that shit... then what we do from now on just doesnt matter. Like we could, I dont know, maybe you and I could. Well."

"Yeah."

"Yeah?"

"Yeah."

"Ill be right over."

[Telephone call between two local customers in Boise, ID, 4/8/05] Fuck you! With a baby screaming in the crook of his left arm he lifted his shiny pistol and fired again. Bannerman Clark wondered if the man was evenaiming. He certainly wasn't hitting anything. Fuck you, he yelped with every shot. His voice had gone hoarse with it.

With a hand signal Clark sent Squad Three forward to back the man up. The infected citizens of Fountain, Colorado spun and dropped and beat their heels against the sidewalk, one after the other. After the fall of Denver the soldiers knew to take their time and line up perfect head shots. Anything else was a waste of ammunition.

The man with the nickelplated revolver couldn't seem to bring his arm down. He wore a blue buttoned-down Oxford cloth shirt and tan chinos smudged with what might have been engine grease. Clark was pretty sure it wasn't. Somebody... the man rasped, somebody take this baby... it's not mine, oh, fuck. He closed his eyes and Clark rushed up to grab the infant before the man dropped it. He knew that look, had seen it hundreds of times before. Fuck, he screeched, and started to fold up, his knees turned to gelatin.

Someone get this man a survival blanket. He's in shock, Clark shouted but before anyone could obey the order Clark heard the chittering spring-loaded sound of a cheap firearm being cocked. He looked down and saw the revolver pointed up at his face. He could feel the heat coming out of the barrel, smell the spent powder.