"The Heart of a Woman," by Baroness Orczy, describes the murder of two young men, one in Brussels and one in London, each in a carriage with a stiletto through the throat. In the latter case, the murder weapon, a stiletto stick, is unmistakably Luke's, and he is recognized to have argued with the victim in a club just before. Luke is defending his elderly Uncle Radclyffe, a surrogate father to him, who had also killed twice to protect the inheritance of the only member of the family's younger generation that Radclyffe cares for - Luke. Radclyffe becomes terminally ill before he can explain his actions or motives to anyone. Will Louisa, Luke's beloved fiance defend him after he is charged with murder?