Mark Aaron's quest to protect history continues as he faces his most dangerous adversary yet, Three, a fellow android from the future, whose goal is to apply 21st century tactics to change the outcome of the American civil war and bring a speedy victory for the Confederacy. Mark, and his companion Jane, must utilize all of their resources, form an alliance with an uncanny being, and become what they abhor in order to preserve history, preserve the union, and save humanity from ultimate destruction.