The Adventure of the Bruce-partington Plans: Easyread Large Edition | Arthur Conan Doyle
Arthur Conan Doyle's The Adventure of the Bruce-Partington Plans (1912) features Mycroft, Sherlock Holmes' brother. The intricate plot involves stolen manuscripts containing designs of the Bruce-Partington submarine. The documents are of national importance, but their recovery is hindered by murder, missing persons, and treason.