Leopold Ernst George Mortimer—Earl, defender of the Crown, spy in the service of the king—is left for dead in a field in rural Denmark. Marie Sophie, impoverished Danish royalty, must flee her country to avoid an arranged marriage. But a woman on her own is not safe. So when she discovers Leo, who has lost his memory from a battle wound, she tells him they're married. By the time they arrive in London, all Leo knows is that his mysterious wife has secrets. Is Marie Sophie the irrepressibly wonderful woman who makes his heart sing, or is she a dangerous spy bent on his destruction?