At 19, Kay Black is probably the most talented assassin the Ministry of Births has ever produced. Her career is going brilliantly, although she is troubled by odd shifts in consciousness and vaguely unsettling feelings that she can neither control nor fully comprehend.
Then a routine assignment to terminate Angela Potemkin, a renowned scientist with the Central Office for Genetic Research, does not go as planned. Angela had somehow known Kay was coming and, although resigned to her fate, she reveals that she knows more about Kay than she should, far more than Kay knows about herself. The information turns Kay's world upside down, and her search for the truth about her origins reveals that she has received an inheritance, something that makes her ever more dangerous than an assassin.
The trouble is she is not alone in receiving this unexpected gift, a gift that by its very nature will challenge the foundations of power in the world ... if Kay can survive long enough to use it.