Roy Grace never dreamed a murder investigation would take him deep into Buckingham Palace . . .Her Majesty, Queen Camilla, is aboard the Royal Train heading to a charity event in Sussex when disaster strikes - the train is derailed.A tragic accident or a planned attack?When, minutes later, a trusted aide is shot dead by a sniper, the police have their answer.Despite all the evidence, Roy Grace is not convinced The Queen was the intended target. But he finds himself alone in his suspicions.Fighting against the scepticism of his colleagues and the Palace itself, Grace pursues his own investigation. But when there is a second murder, the stakes rise even higher, and Grace is at risk of being embroiled in a very public catastrophe - and in mortal danger.Failure at this level is not an option. But time is running out before a killer in the Palace will strike again . . .Roy Grace is back with his most difficult case yet in the gripping new instalment from number one bestselling author Peter James.Available for pre-order now!23 million books sold.Now a major ITV/BritBox show starring John Simm as Roy Grace.Creator of Her Majesty Queen Camilla's favourite fictional detective.'Peter James is one of the best British crime writers and therefore one of the best in the world' - Lee Child, author of the Jack Reacher series'Peter James is one of the best crime writers in the business' - Karin Slaughter, author of the Will Trent series'One of the world's most popular detective series' - The Guardian