Holmes decides to begin with some spies known to him and is then astonished to hear from Dr. Watson that one of those that he names, Eduardo Lucas, has been murdered.

Before Holmes has a chance to act, Lady Hilda Trelawney Hope, the European Secretary's wife, arrives unexpectedly at 221B Baker Street.

It can only mean that the constable guarding the crime scene has been foolish enough to let someone in and leave them alone while they moved things in the room, including the carpet.

At Holmes's suggestion, the document is put back in the dispatch box using Lady Hilda's duplicate key.

When Hope arrives back home with the Prime Minister, Holmes pretends to believe that the evidence has convinced him that the document must still be in the box, shuffled between other papers.

In "The Naval Treaty", Watson says that this case has "interest of such importance and implicates so many of the first families in the kingdom that for many years it will be impossible to make it public."

On the other hand, Watson also refers there to "Monsieur Dubuque of the Paris police, and Fritz von Waldbaum, the well-known specialist of Dantzig, both of whom had wasted their energies upon what proved to be side-issues" who do not appear in the published version of the story.

A spy called Oberstein appears both in this story and in "The Adventure of the Bruce-Partington Plans" (again listed as one of the three most prominent agents in London), set seven years later.

[4] It was included in the short story collection The Return of Sherlock Holmes,[4] which was published in the US in February 1905 and in the UK in March 1905.

A short silent film adapted from the story was released in 1922 as part of the Stoll film series starring Eille Norwood as Sherlock Holmes and Hubert Willis as Watson, and featuring Dorothy Fane as Lady Hope and Wallace Bosco as Eduardo Lucas.

[9] The story was adapted in the Granada Television series The Return of Sherlock Holmes, starring Jeremy Brett, in 1986.

The adaptation contains a chronological error as Holmes is seen skipping past the Clive of India Memorial in King Charles Street, London.

The episode was adapted by Edith Meiser and aired on 23 June 1932, with Richard Gordon as Sherlock Holmes and Leigh Lovell as Dr.

[14] Michael Hardwick dramatised the story as a radio adaptation for the BBC Home Service, as part of the 1952–1969 radio series starring Carleton Hobbs as Holmes and Norman Shelley as Watson, with Simon Lack as Trelawney Hope and Barbara Mitchell as Mrs Hudson.