4.5★s Lord John and the Private Matter is the first novel in the Lord John Grey series by popular American author, Diana Gabaldon. As he waits for his next posting, Lord John Grey, a Major in His Majesty's 47th Regiment, learns of the death of a Sergeant well known to him. Something is off when he pays the widow a condolence visit, and his friend, Colonel Harry Quarry reveals that Sergeant O'Connell was suspected of being a spy. The man they had shadowing him has disappeared and Grey is set the task of investigating. At the same time, quite by chance, Grey comes across a disturbing fact about the Hon. Joseph Trevelyan, the prospective husband of his niece, Olivia Pearsall. As Grey makes enquiries to confirm or dismiss his concerns, he discovers more alarming details, and the boundaries between his two fields of investigation begin to blur. Before Grey finally learns what has transpired, he will visit a brothel and a molly house, examine two dead bodies, acquire a new valet, suffer mercury poisoning, encounter cross-dressers, drink quite a bit of German wine, adjudicate in a fight over a corpse, and board a ship headed for India. There are plenty of twists and turns before the exciting climax of this rather enjoyable piece of historical fiction.