Europol Agent Tom Brindle is called to Barcelona, Spain, to track down the notorious serial killer known as Pygmalion. A set of fingerprints lead to a young, volatile soldier, Marco Soler. Agent Brindle arrests Marco and intensely interrogates him, convinced that he has his man. Marco has an airtight alibi though and further investigation of the suspect leads Agent Brindle to a shocking discovery. Marco was born in a fertility clinic where the eggs of a woman were fertilized, creating the early stages of an embryo. The embryos were then split and one was brought to term as a baby and the other was frozen and released into the donor pool ten years later. The result was identical, monozygotic twins with perfect DNA matches, only a decade apart. They decide to build a psychological and physiological profile of the serial killer using his twin brother, Marco. The hunter becomes the hunted as Pygmalion also discovers that he has a twin bother and begins to stalk the investigative team.