Dr. Kate Warner
Dr. Kate Warner is a geneticist and the protagonist of the Origin Mystery series. While running from pursuers, she attempts to find a cure for the terrible plague that's ravaging the world. She is strong, idealistic, dedicated, and brilliant, and she will stop at nothing to save humanity from near-extinction. It is revealed in the course of the novel that Kate is the modern reincarnation of Janus, the Atlantean who gave the Atlantis gene to humanity in the first place; Kate is therefore an Atlantean herself, and she must work against the efforts of her own people to make humanity transcend itself.
David Vale
David is a major character from the first novel, an ex-military soldier-for-hire who goes on the run with Kate, trying to help her save humanity by discovering the key to the Atlantis gene. Although he died at the end of The Atlantis Gene, this novel sees him resurrected twice by two different Atlanteans, and he rejoins Kate as she tries to stop the plague. He is a harder, less compassionate man than he was before his resurrection, but he is still inwardly the same person who is dedicated to Kate and to saving humanity.
Dorian Sloane
Dorian Sloane was a major antagonist of the last novel, being a ranking officer in the Nazi stronghold of the Atlanteans in Antarctica. David killed him at the end of The Atlantis Gene, but he is also resurrected by the same Atlantean who resurrects David. He kills David again, and the Atlantean (Ares) reveals that Dorian is actually an Atlantean, Ares himself in fact, in a different incarnation. This novel seems to set Dorian up to be the ultimate villain in the third novel.
Martin
Martin is Kate's adopted father, and he works with her in the clinic in her attempt to stop the plague. It is revealed early on, however, that he knows far more than he lets on, and he is the main source of information to catch Kate up to speed on the current state of the world and the effects of the Atlantis Plague and its temporary preventative medicine, Orchid.
Janus
Janus is a powerful Atlantean, the one who injected humans with the Atlantis Gene 70,000 years ago. Kate is actually the modern incarnation of Janus, who resurrected David after Dorian killed him for a second time. Janus is the embodiment of the desire to save humanity rather than have it evolve in a crude, Darwinian style, which Ares is trying to catalyze. The conflict between Janus (Kate) and Ares (Dorian) foreshadows the final battle between the two in the third installment of the series, The Atlantis World.
Ares
Ares is the other Atlantean character in the novel, and he inhabits Dorian, a villain from the previous novel and an all-around terrible person. He believes that the humans who possess the Atlantis gene deserve to rise above the others, and he desires the forced evolution of the human race in a Darwinian "survival of the fittest" style of natural selection. Ares, being a reference to the Greek god of war, is the main antagonist of the series.
