Dorchester Terrace / Anne Perry.

Enhanced descriptions from Syndetics:

Anne Perry's acclaimed Charlotte and Thomas Pitt novels have made London's exclusive world of wealth and power an addictive literary destination for readers everywhere. This new masterpiece, a haunting story of love and treason, invites us not only into the secret places of Britain's power but also into the innermost sanctums of the fin de siècle Austro-Hungarian Empire.

Thomas Pitt, once a lowly policeman, is now the powerful head of Britain's Special Branch, and some people fear that he may have been promoted beyond his abilities. He, too, feels painful moments of self-doubt, especially as rumors reach him of a plot to blow up connections on the Dover-London rail line--on which Austrian duke Alois Habsburg is soon to travel to visit his royal English kin.

Why would anyone destroy an entire train to kill one obscure Austrian royal, or are the rumors designed to distract Pitt from an even more devastating plot? He must resolve this riddle at once, before the damage is done.

Meanwhile, in a London sickroom, an old Italian woman--at the end of a romantic career as a revolutionary spy--is terrified that as she sinks into dementia, she may divulge secrets that can kill. And a beautiful young Croatian woman, married to a British power broker, hoards her own mysteries. Apparently all roads lead to the Continent, and Pitt suspects that between them these two fascinating women could tell him things he desperately needs to know. But as the hours tick by, it seems that the only woman Pitt can count on is his clever wife, Charlotte.

No one sustains mesmerizing suspense better than Anne Perry.  In Pitt's trial by fire, his wrenching moral dilemma, and his electrifying moment of decision, the beloved bestselling author gives us a climax never to be forgotten.