Sir James Walter was a renowned expert and civil servant in the employ of the British government. He was regarded as unfailingly patriotic and well-respected, and as a result was appointed as the official guardian of the top-secret Bruce-Partington submarine plans. Regrettably, the theft of the plans from his office in Woolwich Arsenal caused him such a severe shock that he died almost immediately afterwards, before Sherlock Holmes had a chance to interview him. Had he survived, Sir James would no doubt have been extraordinarily ashamed to discover the thief was in fact his younger brother, Colonel Valentine Walter, working in tandem with the spy Hugo Oberstein.