After attending a medical conference in Beijing and coming frighteningly close to dying in a car crash, Dr. Matthew Nolan arrives home and is immediately arrested at London's Heathrow Airport. Exhausted and confused, Nolan is accused of the murder of a woman who was in the car he crashed. Despite his protests that he was driving alone, Nolan is set to return to China to face charges. 

DC Hana Li is the no-nonsense London officer charged with accompanying Nolan back to Beijing. Her resentment for this assignment, and of Nolan himself, is immediate. However, in flight, when a first death occurs, DC Li begins to suspect foul play. Further deaths confirm that Nolan is in danger, and after a call from MI5, Hana finds herself embroiled in an escalating conspiracy.