Un asunto privado ( A Private Affair: Season 1 )

Marina, An eligible single woman and sister to the city's police chief unexpectedly surprises a man who is stabbing a woman. Marina and her instinct as a detective with the help of loyal butler Hector will start to investigate the crime.

Marina and Hector, with the aid of Pablo uncover the identity of the serial killer.

After detaining the killer it seems that Marina will be forced to give up her dream of becoming a cop, but thanks to Castaño the case is reopened. Together they conclude that the killer is still on the loose and the cops propose a plan to catch him: host a masked party for the clients of the House of Water.

After detaining the killer it seems that Marina will be forced to give up her dream of becoming a cop, but thanks to Castaño the case is reopened. Together they conclude that the killer is still on the loose and the cops propose a plan to catch him: host a masked party for the clients of the House of Water.

Marina has been kidnapped by the killer but manages to escape, though in her escape she is badly hurt. With Pablo's help, Héctor discovers the identity of the artist behind the picture of the House of Water, and they decide to seek him out to ask about the killer's identity.

Now that they know where the killer's next victim is, they must get to her before the killer does. But just as Marina is beginning to gain her trust, the masked killer appears. Marina manages to save Margo and promises to give her protection. But Marina will soon discover that no one is who they claim to be and she shouldn't trust the people around her.

Marina finds the killer's mask in Pablo's car and a fight with the cop ensues, until they lose control of the car and crash; a couple of days later she wakes up in her bed.

After discovering that the murders began thirty years before in Orense, Marina, Ramírez and Pablo go there to search for clues to the fleur-de-lis killer's true identity; what they never realised is that all the while the killer has been closer to them than they ever suspected.