 Holmes receives a surprise visit from no less than the Prime Minister and the country s chief foreign diplomat, Lord Trelawney Hope. They ask his assistance in the recovery of a sensitive diplomatic letter stolen mysteriously from the Lord s home. Its contents are so incendiary that they might lead Great Britain into war if they were published. Holmes credits only three active criminals capable of masterminding so audacious a theft, and when one is found stabbed to death on the night in question, The Great Detective correctly surmises that it is not a coincidence. Matters are further complicated by a visit to Baker Street by Lady Trelawney Hope, a visit she wants kept from her husband.