American biologist Dr Roberta Ryder receives a strange letter from her friend Claudine and travels to Paris to see her, only to learn of her shocking death. Ben Hope, now trying to retire, finds his life turned upside down by Roberta's arrival. In a frantic race to Paris to uncover the mystery of Claudine's research, they uncover a global conspiracy that will claim the lives of millions of people... unless Ben can stop it.