The Adventure of the Naval Treaty (Unabridged‪)‬

Sherlock Holmes takes an interest in the case of a British Foreign Office employee who has had an important naval treaty stolen from his office.
"The Adventure of the Naval Treaty", one of the 56 Sherlock Holmes short stories written by Sir Arthur Conan Doyle, is one of 12 stories in the cycle collected as The Memoirs of Sherlock Holmes. It is one of the longest stories in the Sherlock Holmes collections.