"Where?"

"Sacramento General."

"When?"

"Five days ago. But it's a completely different situation. This case involved a forty-two-year-old naturalist sleeping out in the Sierras, some wildflower expert. There was a particular kind of flower or something. Anyway, he was hospitalized in Sacramento. And he had the same clinical course as your daughter-sudden unexplained onset, no fever, painful erythematous reaction."

"And an MRI stopped it?"

"I don't know if he had an MRI," he said. "But apparently this syndrome-whatever it is-is self-limited. Very sudden onset, and very abrupt termination."

"He's okay now? The naturalist?"

"He's fine. A couple of days of bruising, and nothing more."

"Good," I said. "I'm glad to hear it."

"I thought you'd want to know," he said. Then he said he might be calling me again, with some more questions, and would that be all right? I said he could call whenever he wanted. He asked me to call if there was any change in Amanda, and I said I would, and I hung up. …

Amanda had abandoned Cookie Monster, and was standing in the crib, holding on to the railing with one hand and reaching for me with the other, her little fingers clutching air. I picked her up-and in an instant she had my glasses off. I grabbed for them as she squealed with pleasure. "Amanda…" But too late; she threw them on the floor. I blinked.

I don't see well without my glasses. These were wire-frames, hard to see now. I got down on my hands and knees, still holding the baby, and swept my hand across the floor in circles, hoping to touch glass. I didn't. I squinted, edged forward, swept my hand again. Still nothing. Then I saw a glint of light underneath the crib. I set the baby down and crawled under the crib, retrieved the glasses, and put them on. In the process I banged my head on the crib, dropped down low again.

And I found myself staring at the electrical outlet on the wall underneath the crib. A small plastic box was plugged into the outlet. I pulled it out and looked at it. It was a two-inch cube, a surge suppressor by the look of it, an ordinary commercial product, made in Thailand. The input/output voltages were molded into the plastic. A white label ran across the bottom, reading PROP. SSVT, with a bar code. It was one of those stickers that companies put on their inventory. I turned the cube over in my hand. Where had this come from? I'd been in charge of the house for the last six months. I knew what was where. And certainly Amanda didn't need a surge suppressor in her room. You only needed that for sensitive electronic equipment, like computers.

I got to my feet, and looked around the room to see what else was different. To my surprise, I realized that everything was different-but just slightly different. Amanda's night-light had Winnie-the-Pooh characters printed on the shade. I always kept Tigger facing toward her crib, because Tigger was her favorite. Now, Eeyore faced the crib. Amanda's changing pad was stained in one corner; I always kept the stain bottom left. Now it was top right. I kept her diaper-rash ointments on the counter to the left, just out of her reach. Now they were too close; she could grab them. And there was moreThe maid came in behind me. "Maria," I said, "did you clean this room?"

"No, Mr. Forman."

"But the room is different," I said.

She looked around, and shrugged. "No, Mr. Forman. The same."

"No, no," I insisted. "It's different. Look." I pointed to the lampshade, the changing cloth. "Different."

She shrugged again. "Okay, Mr. Forman." I read confusion in her face. Either she didn't follow what I was saying, or she thought I was crazy. And I probably did look a little crazy, a grown man obsessing about a Winnie-the-Pooh lampshade.

I showed her the cube in my hand. "Have you seen this before?"

She shook her head. "No."

"It was under the crib."

"I don't know, Mr. Forman." She inspected it, turning it in her hand. She shrugged, and gave it back to me. She acted casual, but her eyes were watchful. I began to feel uncomfortable. "Okay, Maria," I said. "Never mind."

She bent over to scoop up the baby. "I feed her now."

"Yes, okay."

I left the room, feeling odd.

Just for the hell of it, I looked up "SSVT" on the Net. I got links to the Sri Siva Vishnu Temple, the Waffen-SS Training School at Konitz, Nazi Regalia for sale, Subsystems Sample Display Technology, South Shore Vocational-Technical School, Optical VariTemp Cryostat Systems, Solid Surfacing Veneer Tiles for home floors, a band called SlingshotVenus, the Swiss Shooting Federation-and it went downhill from there.

I turned away from the computer.

I stared out the window.

Maria had given me a shopping list, the items scrawled in her difficult hand. I really should get the shopping done before I picked up the kids. But I didn't move. There were times when the relentless pace of life at home seemed to defeat me, to leave me feeling washed out and hollow. At those times I just had to sit for a few hours.

I didn't want to move. Not right now.

I wondered if Julia was going to call me tonight, and I wondered if she would have a different excuse. I wondered what I would do if she walked in one of these days, and announced she was in love with someone else. I wondered what I would do if I still didn't have a job by then. I wondered when I would get a job again. I turned the little surge suppressor over in my hand idly, as my mind drifted.

Right outside my window was a large coral tree, with thick leaves and a green trunk. We had planted it as a much smaller tree not long after we moved into the house. Of course the tree guys did it, but we were all out there. Nicole had her plastic shovel and bucket. Eric was crawling around on the lawn in his diapers. Julia had charmed the workmen into staying late to finish the job. After they had all gone I kissed her, and brushed dirt from her nose. She said, "One day it'll cover our whole house."

But as it turned out, it didn't. One of the branches had broken off in a storm, so it grew a little lopsided. Coral is soft wood; the branches break easily. It never grew to cover the house. But my memory was vivid; staring out the window, I saw all of us again, out on the lawn. But it was just a memory. And I was very afraid it didn't fit anymore. After working for years with multi-agent systems, you begin to see life in terms of those programs.

Basically, you can think of a multi-agent environment as something like a chessboard, and the agents like chess pieces. The agents interact on the board to attain a goal, just the way the chess pieces move to win a game. The difference is that nobody is moving the agents. They interact on their own to produce the outcome.

If you design the agents to have memory, they can know things about their environment. They remember where they've been on the board, and what happened there. They can go back to certain places, with certain expectations. Eventually, programmers say the agents have beliefs about their environment, and that they are acting on those beliefs. That's not literally true, of course, but it might as well be true. It looks that way.

But what's interesting is that over time, some agents develop mistaken beliefs. Whether from a motivation conflict, or some other reason, they start acting inappropriately. The environment has changed but they don't seem to know it. They repeat outmoded patterns. Their behavior no longer reflects the reality of the chessboard. It's as if they're stuck in the past. In evolutionary programs, those agents get killed off. They have no children. In other multi-agent programs, they just get bypassed, pushed to the periphery while the main thrust of agents moves on. Some programs have a "grim reaper" module that sifts them out from time to time, and pulls them off the board.