Yet the emissary was fashioned out of a flexible liquid crystal that looked like thick mercury. The creature moved toward the transparent curved wall of the environment chamber. The eerie molten features moved, the lips formed words. “I bear a message from the hydrogues to you, Frederick, king of the rock dwellers.”

“He’s dressed like a Roamer,” said one of the awestruck protocol ministers. Some of the royal guards and court attendees crowded into the Throne Hall now murmured with anger, wondering what that might mean.

The deep-core aliens could not simply have chosen a generic approximation of a human form. This image included too many exact details, too many precise contours. It was an identity stolen or copied from somewhere. Since the hydrogues had destroyed at least five Roamer skymine installations, perhaps they had duplicated one of their victims, absorbed or mimicked his body and clothing in every detail.

King Frederick calmed himself, knowing how much was at stake. “You call yourselves hydrogues?” He tried to keep the quaver from his voice. “We know nothing about your civilization or your species. We did not even know of your existence. From such ignorance, mistakes are made.”

Always be careful. Choose your words. Be vague. Do not assign blame. He had learned the tenets of diplomacy, but such techniques had been developed for humans to deal with humans. Who could tell how a liquid-crystal alien from a gasgiant planet would interpret them?

The Teacher compy OX entered the Throne Hall, unnoticed in the tension, and stood patiently near the green priest and his potted treeling. OX took in all the details, but remained silent until the King should ask him for advice.

“Hydrogue civilization has existed longer than any rockdwelling settlement,” the alien emissary said, its expressions shifting sluggishly, like solder melting into a pool and then hardening again. “Within our worlds, mobile cities are encased in diamond. Our people move from planet to planet in our empire through transgates, only rarely traveling across space in self-contained vessels.” The emissary paused.

King Frederick asked the expected question. “What are transgates? We are unfamiliar with your technology.”

“Dimensional doorways that allow instantaneous journeys from world to world. Though our warglobes and some of our cities are capable of space travel, we find it an inefficient method of making a journey from point to point.”

Frederick tried to grasp the information. Beside him, the green priest droned quietly into the tree, speaking through telink like a stenographer repeating everything he saw and heard. Other green priests across the Spiral Arm would pass on the new information.

These deep-core aliens, these hydrogues, had an entire hidden network of civilization that spanned at least as much area as the Hansa or the Ildiran Empire. But since they lived deep within “uninhabitable” gas giants, traveling through dimensional gates rather than across open space, no human had ever suspected their existence. The depths of his ignorance astonished him.