Sherlock Homes has a son, Sebastian, just graduated from a top European university, and iteching to prove himself more than his famous father's equal. The opportunity presents itself in the run up to the First World War, when his uncle Mycroft introduces him to the First Lord of the Admiralty, an amibitious and bullish young tyro by the name of Winston Churchill. Rumour has it that cabals of U.S. business men plan to exploit their country's official neutrality by selling arms to both sides. Sebastian's job is to infiltrate these circles and uncover the people and the deals by posing as a wealthy private financier ... a task that proves both complex and dangerous.