Description
The film is divided into two separate, unequal stories. In the first and shorter of the two, in August 1887 Holmes is approached by Rogozhin, on behalf of a famous Russian ballerina, Madame Petrova. Madame Petrova is about to retire, and wishes to have a child. She proposes that Holmes be the father, one who she hopes will inherit her beauty and his intellect. Holmes manages to extricate himself by claiming that Watson is his lover, much to the doctor's embarrassment. Back at 221B, Watson confronts Holmes about the reality of the ensuing rumours, and Holmes only states that Watson is "being presumptuous" by asking Holmes whether he has had relationships with women.
In the main plot, a Belgian woman, Gabrielle Valladon, is fished out of the River Thames and brought to Baker Street. She begs Holmes to find her missing engineer husband. The resulting investigation leads to a castle in Scotland. Along the way, they encounter a group of monks and some dwarfs, and Watson apparently sights the Loch Ness monster. They see both canaries and sulfuric acid being carried into the castle, and conclude that the canaries are used to detect chlorine gas produced when the sulfuric acid is mixed with sea water.
It turns out that Sherlock's brother Mycroft is involved in building a pre-World War I submarine for the British Navy, with the assistance of Monsieur Valladon. When taken out for testing, it was disguised as a sea monster. The dwarfs were recruited as crewmen because they took up less space and needed less air. When they meet, Mycroft informs Sherlock that his client is actually a top German spy, Ilse von Hoffmanstal, sent to steal the submersible. The "monks" are German sailors.
Queen Victoria arrives for an inspection of the new weapon, but objects to its unsportsmanlike nature. She orders the exasperated Mycroft to destroy it, so he conveniently leaves it unguarded for the monks to take (rigging it to sink when it is submerged). Fräulein von Hoffmanstal is arrested, to be exchanged for her British counterpart.
In the final scene some months later, Sherlock receives a message from his brother, telling him that von Hoffmanstal had been arrested as a spy in Japan, and subsequently executed by firing squad. Heartbroken, the detective retreats to his room to seek solace in a 7% solution of cocaine.
