A visit from a distressed Mr James Carlisle Scott, a stage magician, begins a case triggered by the disappearance on stage of his assistant. It is a case that will draw Holmes and Watson into the world of international intrigue where state secrets are bartered. A Prussian diplomat working as an aide to the Kaiser is enraged by Holmes's activities at the theatre where he is appearing as a classical pianist. However, a stormy encounter between the pair inadvertently saves Holmes from certain death. Mycroft is at odds with his brother after a secret deal, struck by the British Government, is discovered by Holmes. The involvement of an old foe threatens to tear Sherlock and Mycroft apart. It is only Holmes's unique skills of observation and deduction coupled with swift, yet comedic, action that can perhaps halt a very public assassination. If the assassin succeeds, there may well be war in Europe.