From Prussia with Love

In this alternate history of the late 19th century, King Ludwig of Bavaria rules a mad empire of lords, ladies, spies, and scientists. When he discovers that his arch enemy, General Bismark, is developing a steam-powered intracontinental balistic missile, he launches his own missile program while enlisting the help of Tom Olam, 20th century time traveler, to sabotage Bismark's missile program.