Gonzalo is a school teacher and father of Alonso, but only Satur and Agustín know he is also Aguila Roja (Red Eagle), a man in a mask who tries to uncover a conspiracy and fight for the poor in the 17th century, using the knowledge he got from his trip to China about fighting techniques. After his wife's death in unknown circumstances he tries to go back to his normal life, using his alter ego to find information and fight against the captain who opresses the people of his village. Along the way he meets with a friend from his childhood, Lucrecia, now made Marchioness due to marriage with Marquis of Santillana.