Ethan had survived the massacre of June 2007 purely by accident. He had been recruited as a last-minute delegate to the annual ESA Conference, and he was at Logan Airport waiting for a flight to Phoenix when the first reports flashed across the TV in the boarding-area lounge. His attention was drawn by the photographs alternating on the screen—chillingly, all of them people he knew. Benson at Yale, Kammerov at Cornell, Neiderman at Edinburgh, Linde at Saint Petersburg. And more, a dozen in all. The caption under the newscast said UNIVERSITY MURDERS. Ethan moved closer to the screen, already sick with dread; the volume was turned low, but he heard enough of the newscaster’s murmuring to confirm his fears. There is no conclusive evidence linking the various murders which took place on three continents this Wednesday, but it seems more than coincidental that so many well-known academics and scholars should die violently in such a short period of time… Local authorities are cooperating with the police arm of the League of Nations to determine whether the deaths are part of a larger pattern…

The news must just have made the wire services. The Asian and European killings had happened overnight; the American murders were only hours old. And Ethan didn’t need the help of the League of Nations to recognize “a larger pattern.” All of the named victims had been members of the Correspondence Society.

He found a pay phone and placed a call to his office in Amherst. The Society had taught him to distrust telephones—even local calls were routinely bounced through the radiosphere, part of the global telecom radio-relay system—but he hoped a quick call wouldn’t at tract undue attention. The business-class boarding announcement for his Phoenix flight came while he was dialing; he ignored it.

Amy Winslow, Ethan’s office assistant, answered after three rings. “Professor Iverson! Are you okay?”

He kept his voice carefully neutral and told her he was fine. Before he could say anything more, she asked whether he was in Phoenix yet or whether he could come right back to the office. It was terrible, she said. Tommy Chopra had been shot! Shot and killed! A janitor found him dead! The police were everywhere, talking to people, collecting evidence!

Ethan couldn’t disguise his shock. Tommy Chopra was one of his grad students. Tommy was an early riser and a compulsive perfectionist; Ethan had given him a key to his office and Tommy was often there before sunrise, compiling data while the rest of the campus was just flickering to life. According to Amy, he had been shot and killed sometime before seven this morning. No one had seen his assailant.

But it wasn’t Tommy they meant to kill. It was me.

“Can you come back and talk to the police?”

“Of course. In the meantime, call the conference and tell them I had to cancel. The number’s in the literature on my desk. I’ll be right in.”

It was a deliberate lie. Ethan didn’t mean to go anywhere near his office, not that day or ever again.

Instead he drove for two hours directly to the South Amherst apartment where Nerissa had been staying during their “trial separation,” as she liked to call their rehearsal for divorce. He had agreed not to drop in unannounced, but circumstances overruled that polite agreement. He understood very little about what happened to the Society, but his next move was obvious. He needed to tell her what had happened, why this might be the last time she would see him, and what she had to do next.

The green-on-the-inside man stood patiently on the porch. Ethan, inside, watched the man’s image on a monitor mounted above the door and connected to the video camera hidden in the porch rafters. He tried not to wince when, again, the man looked directly into the camera lens.

If this was a simulacrum, it was running some new kind of strategy, since it didn’t appear to be armed and hadn’t tried to disguise its approach. Ethan figured that made it more dangerous, not less.

The camera hookup included a microphone and speaker. Never engage a sim in conversation was one of the rules Ethan had written for himself, based on his and Werner Beck’s theories about the way the hypercolony functioned. But what was the alternative? Throw open the door and putting a load of buckshot into the face of someone who might, just might, be an innocent civilian?

He keyed the microphone and said, “What ever you’re selling, I’m not interested. This is private property. Please leave.”

“Hello, Dr. Iverson.” The sim’s voice was calm and reedy, with an upstate New York accent. “I know who you are, and you know what I am. But I’m not here to hurt you. We have a common interest. May I explain?”

There was no mind in back of those words, Ethan reminded himself. Nothing but a series of highly-evolved algorithms aimed at achieving a strategic result. Engaging in dialogue with such a creature was no more useful than trying to fend off a scorpion by quoting Voltaire. Still, Ethan was curious in spite of himself. “Are you carrying a weapon?”

The simulacrum gave the camera aningratiating smile. “No, sir, I am not.”

“You care to prove that? You can start by taking off your hat and coat.”

The simulacrum nodded and removed its hat. The sim had brown hair and a bald spot at the crown of its head. It shrugged off its jacket, folded it and placed it alongside the hat on a sun-faded Adirondack chair.

“Now your shirt and pants,” Ethan said.

“Really, Dr. Iverson?”

He didn’t answer. The silence lengthened, until the simulacrum began unbuttoning its shirt. Shirt and pants joined hat and coat, revealing the sim’s pale, pot-bellied, impeccably human-seeming body. “Shoes and socks, too,” Ethan said.

“It’s chilly out here, Professor.”

But the creature cooperated. Which left it standing in nothing but a pair of white briefs. A monster in its underwear, Ethan thought.

“Now may I come in and speak to you?”

Ethan threw open the door, leaving only the wire screen between himself and the green-on-the-inside man. Ethan leveled his short-barrel shotgun at the creature’s chest. The sim focused its attention on the gun. “Please don’t shoot me,” it said.

“What do you want?”

“A few minutes of your time. I want to explain something.”

“How about you give me the short version right now?”

“You and some other members of the Correspondence Society are in real and immediate danger. That’s not a threat. I’m not your enemy. We have mutual interests.”

“Why should I believe any of that?”

“I can explain. Whether you believe me is up to you. May I come in?”

Ethan kept the gun leveled and pulled open the screen door with one hand. “Move slowly.”

The simulacrum stepped across the threshold. “Are you going to keep that shotgun on me?”

“I guess not.” Ethan shifted the shotgun to his left hand and let the barrel droop.

“Thank you.”

“This’ll do fine,” Ethan said, taking the shock pistol from where he had tucked it into his belt and forcing the prongs into the sim’s flabby belly as he pulled the trigger.

Three hundred kilovolts. The green-on-the-inside man dropped like a felled tree.

3

THE WALK TO THE LOW-RISE APARTMENT building where Leo Beck lived kept Cassie warm in the face of the wind, but her little brother was beginning to show symptoms of anxiety. He had her left hand in a grip she was afraid would leave her bruised, though Thomas hadn’t held hands with his sister since he was six years old. “Sun’ll be up soon,” she said, trying to distract him. They passed a ponderous slow-moving machine that sent torrents of soapy water into the sewer grates. “Street sweepers already at work, see?” Thomas shrugged.