Sarah looked at Don, her face astonished. Lenore went on. "I know sending us an encrypted message doesn’t make any sense, but that seems to be what the Dracons have done. The beginning of the message is all math stuff, laid out in that symbol set they used before, and the computer gunks say the math describes a decryption algorithm. And then the rest of the message is total gibberish, presumably because it has indeed been encrypted. Get it? They’ve told us how the message is encrypted, and given us the algorithm to unlock it, but they haven’t given us the decryption key to feed into that algorithm to do the actual unlocking. It’s the craziest thing, and—"

"Pause," said Sarah. "How long does she go on?"

"Another two minutes, sixteen seconds," said the machine, and then it added, "She’s quite chatty."

Sarah shook her head and looked at Don. "Encrypted!" she declared. "That doesn’t make any sense. Why in God’s name would aliens send us a message we can’t read?"

Chapter 3

Sarah fondly remembered Seinfeld, although, sadly, it hadn’t aged well. Still, one of Jerry’s bits of stand-up seemed as true today as it had been half a century ago. When it came to TV, most men were hunters, switching from channel to channel, always on the prowl for something better, while women were nesters, content to settle in with a single program. But today, Sarah found herself scanning constantly; the puzzle of the encrypted message from Sigma Draconis was all over the TV and the web. She caught coverage of oddsmakers paying off winners who’d correctly guessed the day on which a reply would be received, fundamentalists decrying the new signal as a temptation from Satan, and crackpots claiming to have already decrypted the secret transmission.

Of course, she was delighted that there had been a reply, but as she continued to flip channels on the giant monitor above the mantel, she reflected that she was also disappointed that in all the years since they’d detected the first message, no other alien radio source had been found. As Sarah had once said in an interview very much like the ones she was looking at today, it was certainly true that we weren’t alone — but we were still pretty lonely.

Her surfing was interrupted each time someone came up to the front door and rang the bell; an image of whoever it was automatically appeared on the monitor. Mostly it seemed to be reporters; there were still a few journalists who did more than send email, make phone calls, and surf the web.

Those neighbors who had lived here on Betty Ann Drive four decades ago knew Sarah’s claim to fame, but most of the houses had changed hands several times since then. She wondered what her newer neighbors made of the succession of news vans that had pulled into her driveway. Ah, well; at least it wasn’t something to be embarrassed about, like the cop cars that kept showing up at the Kuchma place across the road, and, so far, Sarah had simply ignored all the people who had rung her doorbell, but—

My God.

But she couldn’t ignore this.

The face that had suddenly appeared on the monitor was not human.

"Don!" she called, her voice dry. "Don, come here!"

He had gone into the kitchen to make coffee — decaf, of course; it was all Dr. Bonhoff would let either of them have these days. He shuffled into the living room, wearing a teal cardigan over an untucked red shirt. "What?"

She gestured at the monitor. "My… goodness," he said softly. "How’d it get here?"

She pointed at the screen. Partially visible behind the strange head was their driveway, which Carl had shoveled before leaving yesterday. An expensive-looking green car was sitting on it. "In that, I guess."

The doorbell rang once more. She doubted the being pushing the button was actually getting impatient. Rather, she suspected, some dispassionate timer told it to try again.

"Do you want me to let it in?" asked Don, still looking at the picture of the round, blue face, with its unblinking eyes.

"Um, sure," Sarah said. "I guess."

She watched as he made his way to the little staircase leading to the entryway, and began the slow pilgrimage down, one painful step at a time. She followed him and stood at the top of the stairs — and noted that one of her grandkids had forgotten a colorful scarf here. By the time Don reached the door, the bell had sounded a third time, which was the maximum number it was programmed to allow. He undid the deadbolt and the chain, and swung the heavy oak door inward, revealing—

It had been weeks since Sarah had seen one in the flesh — not that "in the flesh" was the right phrase.

Standing before them, gleaming in the sunlight, was a robot, one of the very latest models, she guessed; it looked more sophisticated and sleeker than any she’d seen before.

"Hello," the robot said to Don, in a perfectly normal male voice. It was about five-foot-six: tall enough to function well in the world, but not so tall as to be intimidating. "Is Dr. Sarah Halifax in?"