Buckingham Palace gardens - Anne Perry

In the latest compelling book in Anne Perry's bestselling Pitt series, Inspector Thomas Pitt must navigate the upper echelons of society if he is to find a murderer bold enough to kill in Buckingham Palace.
Early one morning, Inspector Thomas Pitt is awoken by a message from his boss, Narraway. A maid has been murdered. Only when Pitt focuses does he realise the import of what he is being told. The maid worked at Buckingham Palace and Narraway needs his most trusted man to deal with the investigation. The suspects are narrowed down to a group of guests, meeting with the Prince of Wales to discuss the funding for a huge project: the Cape to Cairo railway. The Prince might overlook the unfortunate loss of a maid but the same cannot be said of the Queen, whose return is imminent. If the murderer isn't found, the Queen will veto royal support for the scheme. It rests with Pitt to solve the murder - in doing so he must reconcile his own concept of justice with those who feel it is within their right to make their own laws, whatever the consequences.