In June of 1893, the future Nicholas II travels to London for a royal wedding, bringing with him his private security force ... Rumored to be the target of a professional assassin known only as La Sylphide, and the subject of conspiracies against his life by his own family who covet his future throne, Nicholas is protected by not only private security, but the professional forces of both England and Russia. All of these measures prove inadequate when Prince George of England is attacked by an armed anarchist who mistakes him for Nicholas. As a result, Barker and Llewelyn are brought in to help track down the assassin and others who might conspire against the life of the tsesarevich.