Marcos is an experienced nurse. He works in the night shift of a provincial private clinic. He is applied and professional but has a secret: in some extreme cases he applies euthanasia. Gabriel, a new nurse, shakes the sector: he is young, intelligent and beautiful. Seduces everyone. He soon deciphers Marcos' secret by progressively taking control of his life. Marcos retracts until he discovers that Gabriel also kills, but capriciously. That revelation will force him to confront Gabriel, Marcos knows that only by exposing his true identity will be able to stop him.