Who is Rosemary Whittaker?

When Lottie is abducted, no-one will miss her for some time: her boy-friend moved on that day; her friends think she is still with him; her job is in limbo and after spending Easter with her parents, they won't be expecting any contact. 'I'm not Rosemary Whittaker,' she tells her abductors. Their photograph indicates otherwise. What will their London Boss's verdict be? What will he do with her?