ickly as it had e。 Sunlight poured in again。
Nobody moved。
We waited。
Moments later； the window in the west wall turned dark； in the same way。 I wondered why the swarm didn't enter。 The window wasn't airtight。 The nanoparticles could slide through the cracks without difficulty。 But they didn't even seem to try。 Perhaps this was an instance where network learning was on our side。 Perhaps the swarms had been trained by their experience at the lab to think doors and windows were impermeable。 Maybe that's why they weren't trying。
The thought gave me a hopeful feeling that helped counteract the pain in my knees。 The west window was still dark； when the north window over the sink turned dark again。 Now two swarms were looking in at the same time。 Ricky had said there were three ing toward the building。 He hadn't mentioned the fourth。 I wondered where the third swarm was。 A moment later； I knew。
Like a silent black mist； nanoparticles began to e into the room underneath the west door。 Soon more particles entered； all around the door frame。 Inside the room； the particles appeared to spin and swirl aimlessly； but I knew they would self…organize in a few moments。 Then at the north window； I saw more particles flooding through the cracks。 Through the air…conditioning vents in the ceiling； still more particles rushed downward。 There was no point in waiting any longer。 I got to my feet and stepped from my hiding place。 I shouted for everybody to e out of hiding。 〃Form up in two rows！〃 Charley grabbed the Windex spray bottle and fell into line； grumbling； 〃What do you think our fucking chances are？〃
〃The best they'll ever get；〃 I said。 〃Reynolds rules！ Form up and stay with me！ Let's go…now！〃
If we weren't so frightened； we might have felt ridiculous； shuffling back and forth across the room in a tight cluster； trying to coordinate our movements…trying to imitate a flock of birds。 My heart was pounding in my chest。 I heard a roaring sound in my ears。 It was hard to focus on our steps。 I knew we were awkward； but we got better quickly。 When we came to a wall； we wheeled and headed back again； moving in unison。 I started swinging my arms and clapping with each step。 The others did the same。 It helped our coordination。 And we each fought our terror。 As Mae said later； 〃It was step aerobics from hell。〃 And all the time； we watched the black nanoparticles as they came hissing into the room through cracks in doors and windows。 It seemed to go on for a long time； but it was probably only thirty or forty seconds。 Soon a kind of undifferentiated fog filled the room。 I felt pinpricks all over my body； and I was sure the others felt it； too。 David started moaning again； but Rosie was right beside him； encouraging him； urging him to keep it together。 Suddenly； with shocking speed the fog cleared； the particles coalescing into two fully formed columns that now stood directly before us； rising and falling in dark ripples。 Seen this close； the swarms exuded an unmistakable sense of menace； almost malevolence。 Their deep thrumming sound was clearly audible； but intermittently I heard an angry hiss； like a snake。
But they did not attack us。 Just as I had hoped； the programming deficits worked for us。 Confronted by a cluster of coordinated prey； these predators were stymied。 They did nothing at all。
At least for now。
Between claps； Charley said； 〃Do you believe…this fucking shit…it's working！〃 I said； 〃Yes but maybe…not for long。〃 I was worried about how long David could control his anxiety。 And I was worried about the swarms。 I didn't know how long they'd just stand there before they innovated new behavior。 I said； 〃I suggest we…move toward that…back door behind us…and get the hell out。〃
As we wheeled away from the wall； I angled slightly toward the rear room。 Clapping and stepping in unison； our group moved away from the swarms； which thrummed deeply and followed。
〃And if we get outside； then what？〃 David whined。 He was having trouble staying in sync with the rest of us。 In his panic； he kept stumbling。 He was sweating and blinking rapidly。 〃We continue this way…flocking this way…back to the lab…and get inside…are you willing to try？〃
〃Oh jeez；〃 he moaned。 〃It's so far 。。。 I don't know if 。。。〃 He stumbled again； nearly lost his balance。 And he wasn't clapping with the rest of us。 I could almost feel his terror； his overwhelming urge to flee。
〃David you stay with us…if you go on your own…you'll never make it…are you listening？〃 David moaned； 〃I don't know 。。。 Jack 。。。 I don't know if I can 。。。〃 He stumbled again； bumped into Rosie； who fell against Charley； who caught her and pulled her back to her feet。 But our flock was knocked into momentary disarray； our coordination gone。 Immediately； the swarms turned dense black； coiled and tightened； as if ready to spring。 I heard Charley whisper 〃Oh fuck；〃 under his breath； and indeed； for a moment I thought he was right； and that it was all over。
But then we regained our rhythm； and immediately the swarms rose up； returned to normal。 Their dense blackness faded。 They resumed their steady pulsing。 They followed us into the next room。 But still they did not attack。 We were now about twenty feet from the back door； the same door we had e in。 I started to feel optimistic。 For the first time； I thought it was possible we really might make it。
And then； in an instant； everything went to hell。
* * *
David Brooks bolted。
We were well into the back room； and about to work our way around the freestanding shelves in the center of the room； when he ran straight between the swarms and past them； heading for the far door。
The swarms instantly spun and chased him。
Rosie was screaming for him to e back； but David was focused on the door。 The swarms pursued him with surprising speed。 David had almost reached the door…his hand was reaching for the doorknob…when one swarm sank low； and spread itself across the floor ahead of him； turning it black。
The moment David Brooks reached the black surface； his feet shot out from under him； as if he had stepped on ice。 He howled in pain as he slammed onto the concrete； and immediately tried to scramble to his feet again； but he couldn't get up； he kept slipping and falling； again and again。 His eyeglasses shattered； the frames cut his nose。 His lips were coated with swirling black residue。 He started to have trouble breathing。
Rosie was still screaming as the second swarm descended on David； and the black spread across his face； onto his eyes； into his hair。 His movements became increasingly frantic； he moaned pitifully like an animal； yet somehow； as he slid and tumbled on hands and knees； he managed to make his way toward the door。 At last he lunged upward； grabbed the doorknob； and managed to pull himself to his knees。 With a final desperate movement； he twisted the knob； and kicked the door open as he fell。
Hot sunlight flared into the shed…and the third swarm swirled in from outside。
Rosie cried； 〃We've got to do something！〃 I grabbed her arm as she ran past me toward David。 She struggled in my grip。 〃We have to help him！ We have to help him！〃
〃There's nothing we can do。〃
〃We have to help him！〃
〃Rosie。 There's nothing we can do。〃
David was now rolling on the ground； black from head to toe。 The third swarm had enveloped him。 It was difficult to see through the dancing particles。 It looked as though David's mouth was a dark hole； his eyeballs pletely black。 I thought he might be blind。 His breath came in ragged gasps； with little choking sounds。 The swarm was flowing into his mouth like a black river。
His body began to shudder。 He clutched at his neck。 His feet drummed on the floor。 I was sure he was dying。
〃e on； Jack；〃 Charley said。 〃Let's get the fuck out of here。〃
〃You can't leave him！〃 Rosie shouted。 〃You can't； you can't！〃 David was sliding out the door； into the sunlight。 His movements were less vigorous now； his mouth was moving； but we heard only gasps。
Rosie struggled to get free。
Charley grabbed her shoulder and said； 〃God damn it； Rosie…〃
〃Fuck you！〃 She wrenched free from his grip； she stamped on my foot and in my moment of surprise I let go； and she sprinted across the shed into the next room； shouting 〃David！ David！〃 His hand； black as a miner's； stretched toward her。 She grabbed his wrist。 And in the same moment she fell； slipping on the black floor just as he had done。 She kept saying his name； until she began to cough； and a black rim appeared on her lips。
Charley said； 〃Let's go； for Christ's sake。 I can't watch。〃
I felt unable to move my feet； unable to leave。 I turned to Mae。 Tears were running down her cheeks。 She said： 〃Go。〃
Rosie was still calling out David's name as she hugged him； pulled his body to her chest。 But he didn't seem to be moving on his own anymore。
Charley leaned close to me and said； 〃It's not your fucking fault。〃
I nodded slowly。 I knew what he was saying was true。
〃Hell； this is your first day on the job。〃 Charley reached down to my belt； flicked my headset on。 〃Let's go。〃
I turned toward the door behind me。
And we went outside。
DAY 6
4：12 P。M。
Beneath the corrugated roof； the air was hot and still。 The line of cars st