It's New Year's Eve, December 31, 1999, and Washington, D.C., is under siege. Early in the day, a grisly machine gun attack in the Dupont Circle Metro station leaves dozens dead and the city crippled with fear. A note delivered to the mayor's office pins the massacre on the Digger, a robot-like assassin programmed to wreak havoc on the capital every four hours í¢ŒóŒî until midnight. Only a ransom of $20 million delivered to the Digger's accomplice í¢ŒóŒî and mastermind í¢ŒóŒî will end the death and terror. But the Digger becomes a far more sinister threat when his accomplice is killed in a freak accident while on route to the money drop. With the ransom note as the single scrap of evidence, Special Agent Margaret Lukas calls upon Parker Kincaid, a retired FBI agent and the top forensic document examiner in the country. Somehow, by midnight, they must find the Digger í¢ŒóŒî before he finds them.