Serena, disguised as a frail, wheelchair-bound patient, lay low in the ancient castle estate, secretly gathering evidence that her uncle Vincent had poisoned her parents and embezzled the family fortune. The mysterious mercenary Gabriel was hired to enter the manor and saw through her disguise. After an initial period of testing each other and strategic maneuvering, they formed an offensive and defensive alliance. They broke through family conspiracies, escaped assassin ambushes, confronted powerful arms syndicates, and fought back fiercely in a bloody counter-attack. Serena reclaimed her vast family empire and also found a love with Gabriel, a love forged through life-or-death struggles.