Nikki, Harry and Leo are called to the Dutch Embassy in the wake of a gunman shooting three people - police constables Tom Barlow and Eddie Whitehead, and young mother Klara Van Buren. Klara is the daughter of official ambassador Jonas Van Buren, whose brother Ulrik was shot in a similar situation three years ago, son Jacob has been missing for fifteen years and grandson Jack who has recently disappeared without trace. The two police officers die in hospital, however, Klara manages to survive, and claims that the gunman was her brother Jacob, who had been missing for fifteen years. The news coverage has a strange effect on the Van Buren's au pair, Mary Olivant, who is later found hanged in her apartment, a death which Leo believes is suspicious. When the pathologists come close to uncovering a dark family secret, the Dutch Embassy throw them off the case, and another pathologist, Sabiston, is called in to carry out the postmortems on the two police offers at the ambassador's request. However, Sabiston is not all he seems.