Four years ago, Sienna Kingsley entered a marriage of convenience with Damian Lancaster while secretly seeking a cure for a mysterious poison. Once cured and with Damian's grandfather gone, she asks for a divorce—and this time, he agrees. Only after the divorce does Damian realize that the woman he once took for granted is anything but ordinary. Sienna is one of the country's most renowned surgeons and shares close ties with business mogul Julian York. Beyond medicine, she excels in piano, painting, design, and even combat sports. As Sienna's extraordinary talents and hidden identities are revealed one after another, Damian becomes fascinated by the ex-wife he never truly knew. Meanwhile, Sienna begins to realize that Damian was never just a cure for her condition—he had long since become something far more important.
