New Year's Eve, 1999. A grisly machine gun attack in the Washington, D.C. subway system leaves dozens dead and the city crippled with fear. A note delivered to the mayor's office connects the massacre to the Digger, an emotionless assassin programmed to wreak havoc on the capital at four-hour intervals, until midnight. Only a ransom of 20 million dollars delivered to his accomplice -- and mastermind -- 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 en route to the money drop. With the ransom note as the single scrap of evidence, Special Agent 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 -- before he finds them.