Bored with his own era, the narrator uses a historical index to leap into a past he imagines will be full of danger, secrecy, and excitement. What he finds instead is a grimy, slang-charged city where every wrong word can turn deadly, and his earnest search for the Mafia lands him amid the rival gangs called the Leopards and the Boomer Dukes. His grand romantic notions collapse into chaos when he is beaten unconscious, wakes as rookie patrolman Walter Hutner, and begins to suspect that the street war conceals something far stranger than ordinary crime. As gang loyalties twist, a glowing talking device, a mysterious "zip," and an armed stranger suggest technology beyond anyone's understanding. Sandy Van Pelt, a weary night-shift reporter, is drawn into the same East Harlem nightmare as storefronts shatter, gunfire erupts, and radiation is suddenly reported in the area. Then the sky fills with a silvery dome and a blue-jacketed youth with bizarre weapons advances through the streets. Darkly comic and satirical, the story blends time travel, gang violence, hard-boiled reportage, and alien bureaucracy into a wild meditation on history, power, and the absurdity of trying to control either. This edition has been fully restored with modern typesetting, custom cover design.