Rieda Fernandez, the person behind the golden Venetian mask, is a top agent working for a secret agency managed by a mysterious billionaire. Knife throwing, gunshooting, archery, swordmanship, hand-to-hand combat, martial arts, name it, she mastered all of those. Because of her outstanding skills, unpredictable strategies, and techniques, she is only assigned for the most special, most important, and the deadliest missions. Whatever mission it is, she'll always finish it smoothly, attracting more and more enemies to hunt her down. But with the help of make up, veil, and the mask, Rieda was able to keep her real identity. After waiting for so long to receive a new project, Rieda found herself to encounter the most challenging role she ever got. A 1 year contract to pretend as a household maid of the famous De Guzman Family in order to protect the one and only heir, Derek, who happened to be a delinquent of his school. Will the greatest agent be able to save Derek's life from numerous threats? How far can she go just to pursue the success of her work? Could she hide her true profile until the termination of the contract from the mischievous man? Or, is the time for her to reveal the one who wears the glamorous mask have arrived?