Charles Stross builds a new series with Empire Games, expanding on the world he created in the Family Trade series, a new generation of paratime travellers walk between parallel universes.The year is 2020. It's seventeen years since the Revolution overthrew the last king of the New British Empire, and the newly-reconstituted North American Commonwealth is developing rapidly, on course to defeat the French and bring democracy to a troubled world. But Miriam Burgeson, commissioner in charge of the shadowy Ministry of Intertemporal Research and Intelligence―the paratime espionage agency tasked with catalyzing the Commonwealth's great leap forward―has a problem. For years, she's warned everyone: "The Americans are coming." Now their drones arrive in the middle of a succession crisis.In another timeline, the U.S. has recruited Miriam's own estranged daughter to spy across timelines in order to bring down any remaining world-walkers who might threaten national security.Two nuclear superpowers are set on a collision course. Two increasingly desperate paratime espionage agencies try to find a solution to the first contact problem that doesn't result in a nuclear holocaust. And two women―a mother and her long-lost daughter―are about to find themselves on opposite sides of the confrontation.