Summer, 1915. As Zeppelins rain death upon the rooftops of London, a Member of Parliament throws himself naked into the Thames after giving a pro-German speech; a senior military advisor suggests surrender before feeding himself to a tiger at London Zoo. In desperation, an aged Mycroft Holmes sends ...

Summer, 1915. As Zeppelins rain death upon the rooftops of London, a Member of Parliament throws himself naked into the Thames after giving a pro-German speech; a senior military advisor suggests surrender before feeding himself to a tiger at London Zoo. In desperation, an aged Mycroft Holmes sends to Sussex for the help of his brother, Sherlock.