Bio-anthropologist Dr. Sloan Parker makes a startling discovery: a new species..... of humans. The drama begins as Sloan is working with her mentor, Dr. Ann Coulter, on a criminal case involving a highly intelligent and ruthless serial killer, Randall Lynch. Hours after revealing to Sloan that "there's a genetic anomaly" in the killer's blood, her teacher is found murdered. Undaunted, Soan continues the research with the help of a colleague, Dr. Ed Tate. She learns that the killer's DNA differs from that of other humans-and that he's not alone. It seems that a new breed resembling Homo sapiens has evolved, and it intends to be the dominant species.

Sloan searches for more of the new humans, only to find more puzzles. But she may have found an ally in Tom Daniels-which she needs after Lynch escapes.

Lynch continues his killing spree as Sloan and Ray pursue him; and Sloan and Ed may have a clue to the geographical origin of the new species.

Sloan, Tom and Ed travel to Mexico to search for clues about the origin of the new species, where they make a discovery that may reveal how many of the new humans exist. When they return, Tom investigates his own origins by visiting his boyhood home.

Attwood brings the pillar from the secret city back to the United States so that Sloan, Ed and Tom can investigate its meaning. With its arrival come new dangers for all of them.