A Deepness in the Sky (Zones of Thought Series #2) (Hugo Award Winner)

After thousands of years searching, humans stand on the verge of first contact with an alien race. Two human groups: the Qeng Ho, a culture of free traders, and the Emergents, a ruthless society based on the technological enslavement of minds.The group that opens trade with the aliens will reap unimaginable riches. But first, both groups must wait at the aliens' very doorstep for their strange star to relight and for their planet to reawaken, as it does every two hundred and fifty years.......