A Deepness in the Sky

The plot begins with the discovery of an intelligent alien species on a planet orbiting an anomalous star, dubbed OnOff because for 215 of every 250 years it is dormant, releasing almost no detectable energy. During this period, the planet freezes and its fauna go into hibernation. The planet's inhabitants, called "Spiders" by the humans for their resemblance to arachnids, have reached a stage of technological development very similar to that of Earth's humans in the early 20th century, although humans believe that they may once have been capable of space travel. If this is true, then whoever can establish ties with the aliens first could reap unimaginable rewards; humans have made contact with only one other intelligent (but non-technological) alien species in millennia of travel through the stars. Two human groups launch expeditions to the Spider world: the Qeng Ho (pronounced Chung Ho and named after the explorer Zheng He), traders who have developed a common interstellar culture for humanity; and the Emergents, a civilization that enslaves selected human minds and has only recently re-emerged from a Dark Age.