International bestselling author Patricia Cornwell delivers pulse-pounding thrills in the first book in a series featuring a brilliant and unusual new heroine, cutting-edge cybertechnology, and stakes that are astronomically high. On the eve of a top secret space mission, Captain Calli Chase detects a tripped alarm in the tunnels deep below a NASA research center. A NASA pilot, quantum physicist, and cybercrime investigator, Calli knows that a looming blizzard and government shutdown could provide the perfect cover for sabotage, with deadly consequences. As it turns out, the danger is worse than she thought. A spatter of dried blood, a missing security badge, a suspicious suicide—a series of disturbing clues point to Calli’s twin sister, Carme, who’s been MIA for days.