Centre of Gravity. Ian Douglas

acidly sarcastic attitude, he seemed to specialize in finding exactly the wrong thing to say to his colleagues. Wilkerson so far had managed to keep him from communicating directly with the Turusch. That task was difficult enough without bringing ego and attitude into the mix.

      “This Crustal Tower message,” Kane said, “says a H’rulka ship has been spotted at Arcturus Station. “But as far as I can see, we don’t know jack about them.”

      “The Turusch have mentioned the H’rulka during a number of sessions,” a third voice put in. “They state that the two species share key philosophical concepts.”

      The invisible speaker was a specialist AI variously called Noam or, sometimes, “Chom,” after the twentieth-century linguist, cognitive scientist, and philosopher Avram Noam Chomsky.

      “There was nothing else in Alan’s recording?” Wilkerson asked.

      “No. The AI known as ‘Alan’ effectively ceased to exist upon partition.”

      Wilkerson nodded understanding. An artificial intelligence like Noam, or like the smaller and more mission-specific AI on the Arcturus recon probe, required a certain size, a certain complexity of internal circuitry and processing power in order to maintain the electronic version of consciousness. Details were still sketchy, but the ISVR–120 interstellar probe apparently had elected to split itself into four separate parts. The probe hardware was designed to allow such a division in order to guarantee that its memory made it back home … but the circuitry carrying those memories simply wasn’t adequate to maintain something as complex as a Gödel 2500 artificial intelligence.

      The AI Alan Turing had in effect committed suicide in order to get its information back to Sol.

      Kane dragged down a virtual window, which glowed in the air in front of him and Wilkerson. The data file with what little was known about the H’rulka scrolled down the screen. “Floaters!” Kane said, reading. “The presumption is that they’re intelligent gas bags that evolved in the upper atmosphere of a gas giant.”

      “Interesting, if true,” Wilkerson said, reading. “I’d like to know how they managed to develop a technology capable of building starships without access to metals, fire, smelting, solid raw materials, or solid ground.”

      “What is it they’re supposed to share with the Tushies, Chom?” Kane asked.

      “It is difficult to express,” Noam replied, “as are most Turusch concepts. It appears, however, to be a philosophy based on the concept of depth.”

      “Yeah, yeah. They order things higher to lower, instead of the way we do it.”

      “It’s no different than when we say something is second class,” Wilkerson said, “and mean it’s not as important or as high-up as first class.”

      “It’s still bass-ackward,” Kane said.

      “The three conscious minds of a Turusch are considered by the Turusch to range from ‘high’ to ‘here’ to ‘low,’” Noam pointed out, “with ‘high’ being the most primitive, most basic state of intelligence, and ‘low’ the most advanced and complex. For the Turusch, something called the Abyss represents depth, scope, danger, and tremendous power. We think the Turusch evolved to live on high plateaus or mountaintops on their world, with lower elevations representing sources of wealth or power—maybe a food source—as well as deadly windstorms. Abyssal whirlwinds, they call them.”

      “So, if the H’rulka are Jovian-type floaters,” Wilkerson mused, “they might relate to the idea of the Abyss as the depths of a gas giant atmosphere. Hot, stormy, high energy, and definitely dangerous. A point of cognitive contact or understanding between them and the Turusch.”

      “Sounds far-fetched to me,” Kane said. “Besides, intelligence couldn’t develop in a gas giant atmosphere. Absolutely impossible.”

      “I’ve learned in this business to mistrust the phrase ‘absolutely impossible,’ Doctor,” Wilkerson said. “Why do you think that?”

      “Because the vertical circulation of atmospheric cells in a gas giant atmosphere would drag any life form in the relatively benign higher levels down into the depths in short order,” Kane replied. “They would be destroyed by crushing pressures and searing high temperatures. There’d be no way to preserve culture … or develop it, for that matter. No way to preserve historical records … art … music … learning. And, as you just said, they wouldn’t get far without being able to smelt metals or build a technology from the ground up.” He smirked. “No ground.”

      “But we do have lots of examples of Jovian life,” Wilkerson said.

      “None of it intelligent,” Kane replied. “It can’t survive long enough.”

      “Maybe.” Wilkerson moved his hand, and the columns of writing on the virtual window were replaced by the image received by the ONI a few hours before … a transmission from a burned-out interstellar probe that had dropped into the outskirts of the Sol System and beamed its treasure trove of data in-system that morning.

      An alert with raw-data footage had been passed on to a number of government offices and military commands a few hours ago; the fact that the H’rulka were at Arcturus was big news. It meant, potentially, disaster. …

      “Whether they’re gas bags from a Jovian atmosphere, or something more substantial,” Wilkerson observed, “they mean trouble. We’ve only met them once, but that was enough.”

      The ongoing exchange of hostilities known as the First Interstellar War had been proceeding off and on for the past thirty-six years. It had begun in 2368 at the Battle of Beta Pictoris, with a single Terran ship surviving out of a squadron of eight. In the years since, defeat had followed defeat as the Turusch and their mysterious Sh’daar masters had taken world upon human-colonized world, as the area controlled by the Terran Confederation had steadily dwindled.

      Most of those defeats were suffered by Earth’s navies at the hands the Turusch va Sh’daar, a species that appeared to be the equivalent of the Sh’daar empire’s military arm. Once, however, a dozen years ago, a Confederation fleet approaching a gas giant within the unexplored system of 9 Ceti, some 67 light years from Sol, had been wiped out by a single enormous vessel rising from the giant’s cloud layers. A single message pod had been launched toward the nearby human colony of Anan, just seventeen light years away, at 37 Ceti.

      The Agletsch, the spidery sentients who’d been Humankind’s first contact with other minds among the stars, had looked at images from that pod and identified the lone attacking ship as H’rulka. The name was an Agletsch word meaning, roughly, “floaters.” They’d claimed that the aliens were huge living balloons that had evolved within the upper atmosphere of a distant gas giant like Sol’s Jupiter. The term H’rulka va Sh’daar suggested that the H’rulka, like the Turusch and like the Agletsch, were part of the galaxy-spanning empire of the Sh’daar.

      No one knew what the H’rulka called themselves, what they looked like, or anything at all about them. Many human researchers, like Kane, were convinced that even the information about a gas giant homeworld was either mistaken or deliberate misinformation.

      What was known was that a few weeks after the fleet at 9 Ceti was lost, all contact with Anan was lost as well.

      If the H’rulka were at Arcturus, apparently working with the Turusch, it suggested that the Sh’daar had just upped the ante, bringing up some big-gun support for their Turusch allies.

      “We could start talking to our Turusch about whether they’ve worked with the H’rulka before,” Wilkerson suggested. “It might give us some insight into how they fit in with the Sh’daar hierarchy.”

      Three millennia earlier, Sun Tse had pointed out that a man who knew both himself and his enemy would be victorious in all of his battles. That might have worked for the ancient Chinese, but complete knowledge simply wasn’t possible—certainly not of beings as completely alien as the Sh’daar, the H’rulka,