pid； minimally programmed； and cooperating by accident。 A lot of behavior looked smarter than it was。 （As Charley Davenport used to say； 〃Ricky should thank God for that。〃） And finally； I didn't really believe that the swarms were dangerous。 I didn't think that a three…pound cloud of nanoparticles could represent much of a threat to anything； not even a rabbit。 I wasn't at all sure it had been killed。 I seemed to recall that rabbits were nervous creatures； prone to die of fright。 Or the pursuing particles might have swarmed in through the nose and mouth； blocking the respiratory passages and choking the animal to death。 If so； the death was accidental； not purposeful。 Accidental death made more sense to me。 In short； I thought that Ricky and the others had consistently misinterpreted what they saw。 They'd spooked themselves。
On the other hand； I had to admit that several unanswered questions nagged at me。 The first； and most obvious； was why the swarm had escaped their control。 The original camera swarm was designed to be controlled by an RF transmitter beaming toward it。 Now apparently the swarm ignored transmitted radio mands； and I didn't understand why。 I suspected an error in manufacturing。 The particles had probably been made incorrectly。 Second was the question of the swarm's longevity。 The individual particles were extremely small； subject to damage from cosmic rays； photochemical decay； dehydration of their protein chains； and other environmental factors。 In the harsh desert； all the swarms should have shriveled up and died of 〃old age〃 many days ago。 But they hadn't。 Why not？ Third； there was the problem of the swarm's apparent goal。 According to Ricky； the swarms kept ing back to the main building。 Ricky believed they were trying to get inside。 But that didn't seem to be a reasonable agent goal； and I wanted to look at the program code to see what was causing it。 Frankly； I suspected a bug in the code。 And finally； I wanted to know why they had pursued the rabbit。 Because PREDPREY didn't program units to bee literal predators。 It merely used a predator model to keep the agents focused and goal…oriented。 Somehow； that had changed； and the swarms now appeared to be actually hunting。
That； too； was probably a bug in the code。
To my mind； all these uncertainties came down to a single； central question…how had the rabbit died？ I didn't think it had been killed。 I suspected the rabbit's death was accidental； not purposeful。
But we needed to find out。
I adjusted my portable radio headset； with the sunglasses and the video camera mounted by the left eye。 I picked up the plastic bag for the rabbit's body and turned to the others。 〃Anybody ing with me？〃
There was an unfortable silence。
Ricky said； 〃What's the bag for？〃
〃To bring the rabbit back in。〃
〃No fucking way；〃 Ricky said。 〃You want to go out there； that's your business。 But you're not bringing that rabbit back here。〃
〃You've got to be kidding；〃 I said。
〃I'm not。 We run a level…six clean environment here； Jack。 That rabbit's filthy。 Can't e in。〃
〃All right； then； we can store it in Mae's lab and…〃
〃No way； Jack。 Sorry。 It's not ing through the first airlock。〃 I looked at the others。 They were all nodding their heads in agreement。
〃All right； then。 I'll examine it out there。〃
〃You're really going to go out？〃
〃Why not？〃 I looked at them； one after another。 〃I have to tell you guys； I think you've all got your knickers in a twist。 The cloud's not dangerous。 And yes； I'm going out。〃 I turned to Mae。 〃Do you have a dissection kit of some kind that…〃
〃I'll e with you；〃 she said quietly。
〃Okay。 Thanks。〃 I was surprised that Mae was the first to e around to my way of seeing things。 But as a field biologist； she was probably better than the others at assessing real…world risk。 In any case； her decision seemed to break some tension in the room； the others visibly relaxed。 Mae went off to get the dissecting tools and some lab equipment。 That was when the phone rang。 Vince answered it； and turned to me。 〃You know somebody named Dr。 Ellen Forman？〃
〃Yes。〃 It was my sister。
〃She's on the line。〃 Vince handed me the phone； and stepped back。 I felt suddenly nervous。 I glanced at my watch。 It was eleven o'clock in the morning； time for Amanda's morning nap。 She should be asleep in her crib by now。 Then I remembered I had promised my sister I would call her at eleven to check in； to see how things were going。 I said； 〃Hello？ Ellen？ Is everything all right？〃
〃Sure。 Fine。〃 A long； long sigh。 〃It's fine。 I don't know how you do it； is all。〃
〃Tired？〃
〃About as tired as I've ever felt。〃
〃Kids get off to school okay？〃
Another sigh。 〃Yes。 In the car； Eric hit Nicole on the back； and she punched him on the ear。〃
〃You've got to interrupt them if they start that； Ellen。〃
〃So I'm learning；〃 she said wearily。
〃And the baby？ How's her rash？〃
〃Better。 I'm using the ointment。〃
〃Her movements okay？〃
〃Sure。 She's well coordinated for her age。 Is there a problem I should know about？〃
〃No； no；〃 I said。 I turned away from the group； lowered my voice。 〃I meant； is she pooping okay？〃
Behind me； I heard Charley Davenport snicker。
〃Copiously；〃 Ellen said。 〃She's sleeping now。 I took her to the park for a while。 She was ready to go down。 Everything's okay at the house。 Except the pilot for the water heater went out； but the guy's ing to fix it。〃
〃Good； good 。。。 Listen； Ellen； I'm in the middle of something here…〃
〃Jack？ Julia called from the hospital a few minutes ago。 She was looking for you。〃
〃Uh…huh 。。。〃
〃When I said you'd gone to Nevada； she got pretty upset。〃
〃Is that right？〃
〃She said you didn't understand。 And you were going to make it worse。 Something like that。 I think you better call her。 She sounded agitated。〃
〃Okay。 I'll call。〃
〃How are things going out there？ You be back tonight？〃
〃Not tonight；〃 I said。 〃Sometime tomorrow morning。 Ellen； I have to go now…〃
〃Call the kids at dinnertime； if you can。 They'd like to hear from you。 Auntie Ellen is fine； but she's not Dad。 You know what I mean。〃
〃Okay。 You'll eat at six？〃
〃About。〃
I told her I'd try to call； and I hung up。
* * *
Mae and I were standing by the double glass walls of the outer airlock； just inside the building entrance。 Beyond the glass； I could see the solid…steel fire door that led outside。 Ricky was standing beside us； gloomy and nervous； watching as we made our final preparations。 〃You sure this is necessary？ To go outside？〃
〃It's essential。〃
〃Why don't you and Mae wait until nightfall； and go out then？〃
〃Because the rabbit won't be there；〃 I said。 〃By nightfall； coyotes or hawks will have e and taken the carcass away。〃
〃I don't know about that；〃 Ricky said。 〃We haven't seen any coyotes around here for a while。〃
〃Oh hell；〃 I said impatiently； turning on my radio headset。 〃In the time we've spent arguing about this； we could have been out and back already。 See you； Ricky。〃 I went through the glass door； and stood in the airlock。 The door hissed shut behind me。 The air handlers whooshed briefly in the now…familiar pattern； and then the far glass slid open。 I walked toward the steel fire door。 Looking back； I saw Mae stepping into the airlock。 I opened the fire door a crack。 Harsh； glaring sunlight laid a burning strip on the floor。 I felt hot air on my face。 Over the inter； Ricky said； 〃Good luck； guys。〃 I took a breath； pushed the door wider； and stepped out into the desert。 The wind had dropped； and the midmorning heat was stifling。 Somewhere a bird chittered； otherwise it was silent。 Standing by the door； I squinted in the glare of the sunlight。 A shiver ran down my back。 I took another deep breath。
I was certain that the swarms were not dangerous。 But now that I was outside； my theoretical inferences seemed to lose force。 I must have caught Ricky's tension； because I was feeling distinctly uneasy。 Now that I was outside； the rabbit carcass looked much farther away than I had imagined。 It was perhaps fifty yards from the door； half the length of a football field。 The surrounding desert seemed barren and exposed。 I scanned the shimmering horizon； looking for black shapes。 I saw none。
The fire door opened behind me； and Mae said； 〃Ready when you are； Jack。〃
〃Then let's do it。〃
We set off toward the rabbit； feet crunching on the desert sand。 We moved away from the building。 Almost immediately； my heart began to pound； and I started to sweat。 I forced myself to breathe deeply and slowly； working to stay calm。 The sun was hot on my face。 I knew I had let Ricky spook me； but I couldn't seem to help it。 I kept glancing toward the horizon。 Mae was a couple of steps behind me。 I said； 〃How're you doing？〃
〃I'll be glad when it's over。〃
We were moving through a field of knee…high yellow cholla cactus。 Their spines caught the sun。 Here and there； a large barrel cactus stuck up from the floor like a bristling green thumb。 Some small； silent birds hopped on the ground； beneath the cholla。 As we approached； they took to the air； wheeling specks against the blue。 They landed a hundred yards away。 At last we came to the rabbit； surrounded by a buzzing black cloud。 Startled； I hesitated a st