A Dangerous Climate — Chelsea Quinn Yarbro

The vampire Count Saint-Germain, disguised as a missing Hungarian nobleman, is on a spy mission in the heart of Czarist Russia. Almost by the power of his will alone, it seems, Peter the Great is wrestling the city that will one day be St. Petersburg out of swampland. Representatives of the heads of all European states are living in tiny, frigid, wooden homes as they jockey for power and influence over the Czar. When a man shows up claiming to be the Count Saint-Germain, the vampire must figure out how to protect his title and wealth without revealing either his true identity or his True Nature.