Drake asked to be informed when the probe came within ten light-minutes of its planetary goal, and turned his attention elsewhere. Other messages were streaming in from other places. It was more of the same bad news: planets and their colonies, unaffected in appearance, were vanishing from the universe of communication. They were becoming part of a great and spreading silence.
He measured the total time for fifty more cases of signal loss: a little less than six hours. Allowing for statistical error, Par Leon’s estimate of two hundred lost worlds a day was spot on.
Drake did not try to examine each situation in detail. Melissa and Tom would be doing that, and they would provide their analyses later. He turned his attention back to the first world. The probe was within ten light-minutes. While it flew closer, Drake called for backup planetary data.
This was one world in a triple dwarf-star system of over a hundred. And it was the only one that was even remotely habitable, with native life-forms and an oxygen atmosphere. That gave it a certain distinction: planetary orbits in multiple systems were normally too variable for life to develop, sometimes sweeping in searingly close to one of the stars, then wandering off for cold years in the outer darkness. This world had been lucky — its name translated to Drake as “Felicity.” It had hovered in the middle region, not too close and not too far, for the billion years that life needed.
That’s where its claim to distinction ended. The native life had not progressed beyond cyanobacteria, a coating of blue, green, and sickly yellow that covered the surface of the single ocean and most of the land. For humans interested in planetary transformation, though, Felicity with its surface water and thin oxygen atmosphere was 99 percent of the way there. All that had to be done was a stabilization of the orbit, a boost to the gravitational field, a buildup of the atmosphere, and the introduction of multiple-celled organisms. Trivial. The work had been completed half a billion years ago. Felicity had become a typical member of the teeming galactic family of inhabited worlds.
And now?
The image from the probe was providing better definition as the distance decreased. Drake half expected to see a yellow-streaked globe of sullen red, like Earth when it collapsed to one-tenth of its old size and isolated itself from the rest of the solar system. But he could see surface detail on Felicity. The outline of a single ocean, shaped like a blunt horse’s head and low lit by the glancing light of the triple suns, matched the shape shown in the data bank. He saw the softening of texture that indicated the presence of an atmosphere, and occasional high clouds that confirmed it.
“It looks exactly the same.” That was Par Leon, muttering his surprise. “Nothing at all seems to have happened to it. This was one of the worlds that installed our defense systems. Just a month ago, it told us that they were completed and working. So why doesn’t it reply to us now?”
Drake could suggest a fistful of answers:
• A shield around the planet was inhibiting all outgoing signals or materials; but that clearly could not be the case. Visible wavelength radiation was being reflected from the surface, since the probe could see it. If necessary, anyone down on the surface could use the same wavelengths to send an outgoing signal.
• A shield was stopping all ingoing signals or materials; but that was even worse. The world below the shield would be in total darkness. Clearly it was not, because sunlight was getting through. In any case, other worlds and colonies affected long ago by such a shield would soon have noticed that they were not receiving messages, and either come or call to ask what was going on.
• Something, a deadly ray or a toxic cloud of gas, had wiped out all life on Felicity. The planet would not at once change its appearance if that happened.
• Something had wiped out all intelligent life. It did not have to be fatal; if humans and their inorganic complements had been reduced to the thinking level of a smart dog, no piece of communications equipment — or any other technology — would mean anything.
(Ana, after leaving the home of a couple who swore that their pet was as smart as any human, had said: “No dog, no matter how well bred or well intentioned, can tell you that it came from poor but honest parents. ”
He missed her in a thousand ways, but most of all he missed her humor and her refusal to substitute sentiment for sense.)
Drake jerked his thoughts back to the task at hand:
• The population, for its own reasons, had chosen a policy of total isolationism. If just one world had been affected, that would be wholly plausible. It must have happened a million times. When thousands of neighboring worlds went the same way, though, plausibility became impossibility.
Unless the policy was contagious, an isolationist meme that spread from world to world as a message of irresistible power? But then why hadn’t it traveled at superluminal speed and long ago converted the whole Galaxy? And why had the first world affected been far out on the galactic rim? That suggested an influence borne into humanity’s domain from far, far away.
Well, they would know soon enough. Felicity was looming right ahead.
“Still no response.” Par Leon was losing his nervousness. Drake couldn’t understand why. Didn’t Leon realize that this scenario must have been played out a million or a billion times, when a ship by an accident of timing had approached a world that had just become silent?
“We propose to land,” Leon said. “Do you have any objection?” The probe was swinging into a descent orbit around Felicity’s equator. The nightside view showed a scattering of lights. Cities, and a working power system. The planet still showed the signs of an intact civilization.
“None. Carry on with your landing.” And good luck, Leon.
Something had to happen, and soon. No ship had ever returned a signal from one of the silent worlds. Either it had never reached the surface, or after it did so it could no longer send a message.
On the other hand, no world had ever to Drake’s knowledge possessed its own powerful defenses. Was it as simple as that? Had the defense system done the trick? Was the battle for the Galaxy won already?
He didn’t believe it. Too easy, and it would leave a huge mystery. Who and what were the aggressors?
“We still have no descent problems,” Leon said. “But there is no navigation signal from the surface. We are going into the final entry phase.”
Drake stared at the scene from the probe’s imager. No vanished planet. No mysterious shields. Everything as normal as could be.
While that thought was still forming, a bright spark of violet appeared ahead on the line of the equator. It grew rapidly, blossoming from a point to a soft-edged plume of white and blue.
In the final moment before the fire reached up to envelop the probe, and the S-wave message stream to headquarters ceased, Drake understood several things at once.
First, he was going to learn nothing more about present conditions on the surface of Felicity; because the probe, along with Par Leon and the onboard composite, was doomed. They were about to be destroyed by a flame as hot as the center of a star.
Worse than that, humanity was going to learn nothing about the reason why billions of worlds had been silenced. Whatever had happened to them, it was different from what was happening now on Felicity.
Because the agent for this probe’s destruction was not some alien and unknown force. It was part of a human defensive system; a system that had been designed and defined and described to the inhabitants of Felicity by Cass Leemu, Mel Bradley, and Drake Merlin.
This was no time for meeting in ones and twos. Drake could feel the pressure again, the countless terrified minds clamoring at the gates of the villa. They had been calm when the defenses were going into place, blindly hoping that the problem was solved. Was he the only one who had expected the next sector of the Galaxy to fall? — although even he had been shocked when the observing probes were destroyed by the defenses that he had installed.