At 1:01 A.M. Greenwich Mean Time on December 11, 1999, computer systems all around the globe freeze for twenty seconds, then return to normal. Susan Garnett, a senior analyst at the FBI's high-tech crime unit, discovers that the virus is counting down to the year 2000, when the world's computers will be most vulnerable. Susan traces the virus's signal to a surprising point of origin: an area near Tikal, the site of one of the largest cities of the ancient Maya. With Cameron Slater, an anthropologist, she travels to the remote jungle, where they must draw on their combined knowledge of ancient glyphs and modern algorithms to crack a code hidden in a formidable computer virus. They are convinced that if they fail to solve the riddles both ancient and new before the turn of the new millennium, the virus could trigger a powerful event of global proportions.