Women spies-fiction, Women scientists-fiction 

She used to work for the United States government, but very few people ever knew that. An expert in her field, she was one of the darkest secrets of an agency so clandestine it doesn't even have a name. And when they decided she was a liability, they came for her without warning. Now, she rarely stays in the same place or uses the same name for long. They've killed the only person she trusted, but something she knows still poses a threat. When her former handler offers her a way out, she realizes it's her only chance to erase the giant target on her back. But it means taking one last job for her ex-employers. To her horror, the information she acquires only makes her situation more dangerous. Resolving to meet the threat head on, she prepares for the toughest fight of her life, but finds herself falling for a man who can only complicate her likelihood of survival. As she sees her choices being rapidly whittled down, she must apply her unique talents in ways she never dreamed of.