The corpses of several teenage girls are turning up, abandoned and brutally mutilated, in isolated locations around the Spanish province of Biscay, in the Basque Country. There are no leads on the killer; nobody knows anything about the mysterious assailant, and the only thing that the victims have in common with each other is that they are all lonely young girls.
The investigation brings the young medical examiner Natalia Egaña, along with the murder detective Carlos Vega, to discover that the killer contacts their victims via the Internet. Using the pseudonym of 'Charon', the murderer gradually closes in on them, finding out their most intimate secrets, and winning their love, until finally arranging a lethal date.