Long ago, forensic anthropologist Diane Fallon served in South America at the World Accord International. Years later, haunted by the massacres a continent away, she has been trying hard to put the past behind her. Until now...

Working late at her museum, Diane hears a terrified cry that leads her to an injured man - and recognises him as a fellow WAI staffer from her days in South America. Clutching a child's femur in his hands, he whispers, 'It was one of us...' and dies.

Now Diane is faced with some deadly questions - why was her former colleague trying to visit her? Why did he carry a human bone? Who did he mean by 'us', and just who attacked him? More importantly, is Diane the next on the list?