Adventure of the Bruce-Partington Plans

Sherlock Holmes is very surprised to receive a visit from his brother Mycroft, bringing him the case of Arthur Cadogan West. West was a civil servant found dead on subway tracks at Aldgate, with plans of a top secret submarine plans on his person. According to Mycroft, the plans were kept in a safe whose keys are held by men considered to be above suspicion: Sir James Walter and Sidney Johnson. Arthur Cadogan West was known as a serious employee, and Johnson's deputy. It is believed he stole plans to sell them and was killed during the transaction. But Holmes wonders why Cadogan West had stolen the plans while he could copy them.FultonClassics.com