Due to their unique neurology, only the enslaved Operator caste can program the quantum computers that run 26th century Red City. When three of the caste are ritually murdered, it's up to private investigator Hoshi Archer-herself a recently liberated Operator-to help the police solve the case. Things get complicated when one of the victims turns out to be Hoshi's ex-girlfriend, and power-hungry bureaucrats and old rivals stir up new problems. An immortal, amoral alien may even be involved. To unwind the plot to take over the city, Hoshi must decipher a deadly computer program and learn to communicate with the alien, before it's too late for the next victim-and the city.