When Rachel Covington's twin sister Sarah is murdered, revenge requires making the killers believe Sarah¿s still alive, so the sheltered governess must take on her twin's double role as London's most notorious courtesan and undercover English spy.Sarah's former espionage partner, Sebastian Talbot, is assigned to train and protect Rachel, but he seems more interested in vexing her in every possible way. For Sebastian, the mission is a nightmare, a replay of his failure to save Sarah, but with a woman whose unfamiliar innocence threatens to slip past all the barriers of his cynical soul.Together, they must lure Sarah's murderers into the open, distinguish loyal agents from traitors, and struggle to trust one another. The slightest misstep may mean Rachel's death, so Sebastian must help her play her courtesan role convincingly, and that means awakening her long-buried sensuality, a process which threatens both their professional detachment and their surprisingly vulnerable hearts.