"That's good," he said. "Glad to hear it."

I said, "What about the MRI?"

The doctor said the MRI results were not relevant, because the machine had malfunctioned and had never examined Amanda. "In fact, we're worried about all the readings for the last few weeks," he said. "Because apparently the machine was slowly breaking down."

"How do you mean?"

"It was being corroded or something. All the memory chips were turning to powder."

I felt a chill, remembering Eric's MP3 player. "Why would that happen?" I said. "The best guess is it's been corroded by some gas that escaped from the wall lines, probably during the night. Like chlorine gas, that'd do it. Except the thing is, only the memory chips were damaged. The other chips were fine."

Things were getting stranger by the minute. And they got stranger still a few minutes later, when Julia called all cheerful and upbeat, to announce that she was coming home in the afternoon and would be there in plenty of time for dinner.

"It'll be great to see Ellen," she said. "Why is she coming?"

"I think she just wanted to get out of town."

"Well, it'll be great for you to have her around for a few days. Some grown-up company."

"You bet," I said.

I waited for her to explain why she hadn't come home. But all she said was, "Hey, I got to run, Jack, I'll talk to you later-"

"Julia," I said. "Wait a minute."

"What?"

I hesitated, wondering how to put it. I said, "I was worried about you last night."

"You were? Why?"

"When you didn't come home."

"Honey, I called you. I got stuck out at the plant. Didn't you check your messages?"

"Yes…"

"And you didn't have a message from me?"

"No. I didn't."

"Well, I don't know what happened. I left you a message, Jack. I called the house first and got Maria, but she couldn't, you know, it was too complicated… So then I called your cell and I left you a message that I was stuck at the plant until today."

"Well, I didn't get it," I said, trying not to sound like I was pouting. "Sorry about that, honey, but check your service. Anyway listen, I really have to go. See you tonight, okay? Kiss kiss."

And she hung up.

I pulled my cell phone out of my pocket and checked it. There was no message. I checked the phone log. There were no calls last night.

Julia hadn't called me. No one had called me.

I began to feel a sinking sensation, that descent into depression again. I felt tired, I couldn't move. I stared at the produce on the supermarket shelves. I couldn't remember why I was there.

I had just about decided to leave the supermarket when my cell phone rang in my hand. I flipped it open. It was Tim Bergman, the guy who had taken over my job at MediaTronics. "Are you sitting down?" he said.

"No. Why?"

"I've got some pretty strange news. Brace yourself."

"Okay…"

"Don wants to call you."

Don Gross was the head of the company, the guy who had fired me. "What for?"

"He wants to hire you back."

"He wants what?"

"Yeah. I know. It's crazy. To hire you back."

"Why?" I said.

"We're having some problems with distributed systems that we've sold to customers."

"Which ones?"

"Well, PREDPREY."

"That's one of the old ones," I said. "Who sold that?" PREDPREY was a system we'd designed over a year ago. Like most of our programs, it had been based on biological models. PREDPREY was a goal-seeking program based on predator/prey dynamics. But it was extremely simple in its structure.

"Well, Xymos wanted something very simple," Tim said.

"You sold PREDPREY to Xymos?"

"Right. Licensed, actually. With a contract to support it. That's driving us crazy."

"Why?"

"It isn't working right, apparently. Goal seeking has gone haywire. A lot of the time, the program seems to lose its goal."

"I'm not surprised," I said, "because we didn't specify reinforcers." Reinforcers were program weights that sustained the goals. The reason you needed them was that since the networked agents could learn, they might learn in a way that caused them to drift away from the goal. You needed a way to store the original goal so it didn't get lost. The fact was you could easily come to think of agent programs as children. The programs forgot things, lost things, dropped things. It was all emergent behavior. It wasn't programmed, but it was the outcome of programming. And apparently it was happening to Xymos.

"Well," Tim said, "Don figures you were running the team when the program was originally written, so you're the guy to fix it. Plus, your wife is high up in Xymos management, so your joining the team will reassure their top people."

I wasn't sure that was true, but I didn't say anything.

"Anyway, that's the situation," Tim continued. "I'm calling you to ask if Don should call you. Because he doesn't want to get rejected."

I felt a burst of anger. He doesn't want to get rejected. "Tim," I said. "I can't go back to work there."

"Oh, you wouldn't be here. You'd be up at the Xymos fab plant."

"Oh yes? How would that work?"

"Don would hire you as an off-site consultant. Something like that."

"Uh-huh," I said, in my best noncommittal tone. Everything about this proposal sounded like a bad idea. The last thing I wanted to do was go back to work for that son of a bitch Don. And it was always a bad idea to return to a company after you'd been fired-for any reason, under any arrangement. Everybody knew that.

But on the other hand, if I agreed to work as a consultant, it would get rid of my shelf-life problem. And it would get me out of the house. It would accomplish a lot of things. After a pause, I said, "Listen, Tim, let me think about it."

"You want to call me back?"

"Okay. Yes."

"When will you call?" he said.

The tension in his voice was clear. I said, "You've got some urgency about this…"

"Yeah, well, some. Like I said, that contract's driving us crazy. We have five programmers from the original team practically living out at that Xymos plant. And they're not getting anywhere on this problem. So if you're not going to help us, we have to look elsewhere, right away."

"Okay, I'll call you tomorrow," I said.

"Tomorrow morning?" he said, hinting.

"Okay," I said. "Yes, tomorrow morning."

Tim's call should have made me feel better about things, but it didn't. I took the baby to the park, and pushed her in the swing for a while. Amanda liked being pushed in the swing. She could do it for twenty or thirty minutes at a time, and always cried when I took her out. Later I sat on the concrete curb of the sandbox while she crawled around, and pulled herself up to standing on the concrete turtles and other playthings. One of the older toddlers knocked her over, but she didn't cry; she just got back up. She seemed to like being around the older kids. I watched her, and thought about going back to work.

"Of course you told them yes," Ellen said to me. We were in the kitchen. She had just arrived, her black suitcase unpacked in the corner. Ellen looked exactly the same, still rail-thin, energetic, blond, hyper. My sister never seemed to age. She was drinking a cup of tea from teabags that she had brought with her. Special organic oolong tea from a special shop in San Francisco. That hadn't changed, either-Ellen had always been fussy about food, even as a kid. As an adult, she traveled around with her own teas, her own salad dressings, her own vitamins neatly arranged in little glassine packs.

"No, I didn't," I said. "I didn't tell them yes. I said I'd think about it."

"Think about it? Are you kidding? Jack, you have to go back to work. You know you do." She stared at me, appraising. "You're depressed."

"I'm not."

"You should have some of this tea," she said. "All that coffee is bad for your nerves."