Johan Eschbach, Professor of Environmental Science and semi-retired secret agent, and his lovely wife the world-renowned singer Llysette, return for another adventure, this time in Russia, during the long 'white nights' of summer. Their world is an intriguing alternate present in which many things are changed. What we know as the eastern U.S. is the nation of Columbia, and Russia is still ruled by the Czars. Llysette is being sent by the Columbian government on a cultural exchange mission to St. Petersburg. Johan will, of course, accompany her, allowing him to work behind the scenes on the oil concession in Russian Alaska that Columbia so desperately needs. But even the oil shortage will fade to insignificance when Johan discovers what new weapons technology the Russians are developing, a threat even more fearsome than the atomic bombs of Austro-Hungary. This is the concluding novel of the of alternate history adventure trilogy that Modesitt began with Of Tangible Ghosts and The Ghost of the Revelator.