In particular, the sensation novel habitually focuses on the secrets and secret histories of women. All of Mary Elizabeth Braddon's early novels are structured around women with a concealed past: women who, for a variety of reasons, conceal their present motivations and desires, and who have a hidden mission which drives their lives. In most cases these feminine concealments both result from, and foreground, a tension between the proper and the improper feminine. The secret at the heart of Braddon's novels usually involves a former transgression of the bounds of the proper feminine, or it involves a guilt by association, which taints or threatens the heroine's respectability. The concealment most often results from a conflict between a particular woman's self-appointed mission and the accepted codes of the proper feminine, or from the necessity for women to act by stealth, and often through male agents, in a society which casts them in a passive, dependent role. Except in the case of Braddon's two best-known novels, the secret involves a conflict between the heroine's mission to avenge a wronged father (or fathersubstitute) and that code of the proper feminine which defines woman as self-sacrificing, loving and forgiving. Revenge thus serves as a generalised metaphor for a commanding secret passion, a hidden desire which motivates a woman's actions.