A young gentlewoman, Margaret de Beauchamp, finds her fate twisted into the lives of the up-timers, folks from "West Virginia" and "the future," imprisoned in the Tower of London. In exchange for her help escaping, Rita Simpson and Harry Lefferts give her a huge sum of money to keep her family's manor and its woolen trade from falling into the hands of the crown and its unscrupulous minister, Lord Cork. But money alone is not enough to save her family's trade. When Margaret and the up-timers introduce aqualator computers to save the wool trade and weavers, the young gentlewoman and her new up-timer allies find themselves threatened by spies, raiders, and even pirates.