In near-future Singapore, epidemiologist Ty Kian is a "plague tracker" who hunts bio-terrorists for the W.H.O. He is drawn into a desperate search for the kidnapped daughter of a wealthy widow, Carolyn Yung. Warned off the case by Triad gangsters, Kian perseveres because the missing girl may carry a deadly plague. As Kian and Carolyn work together, they begin a love affair. Kian and botanist friend Nigel Leong analyze drug-laden spices connected to the girl's mysterious kidnapper. They trace the spices to Borneo, where they find the girl, Jade, and her alleged kidnapper, Hong Tao, tending groves of genetically modified spices. They are attacked by the gangsters who want to blackmarket spice trade, but Kian rescues Jade and Nigel. Kian reunites Jade with Carolyn but deduces that Jade is Carolyn's clone, not her natural daughter. Carolyn offers Kian a fortune to keep their secret, so she and Jade can evade Singapore's draconian anti-clone laws. But Kian then discovers that Carolyn needs organ transplants from her clone, Jade. When Kian tries to stop Jade's destruction, only he and Jade survive. Jade then threatens to kill Kian, so no one will know she is a clone and she can inherit her mother's vast wealth. Kian tries to convince Jade that she is not evil like her mother, but Jade replies that she is exactly like Carolyn.