The Darlington Letters: 16 (Rannoch Fraser Mysteries)

Glittering chandeliers reveal dark secrets... Former spies and London society favorites Malcolm and Mélanie Suzanne Rannoch are back home and delighted that their dear friends Raoul ORoarke and Laura Tarrington are finally free to marry. But what should be an occasion for joy is soon/quickly marred by a blackmail attempt. To aid an old friend the Rannochs must resume a life of espionage and adventure facing an attack at the London docks and infiltrating a Mayfair ball in disguise to retrieve stolen letters. They soon realize the stolen documents they seek could upend the British government--and the secrets Malcolm and Mélanie uncover hit unexpectedly--and dangerously--close to home...