to be added
- Holmes and Watson visited Ruritania several times to assist King Rudolf.
- Britain established an alliance with Mars after the Martians' attempted invasion of Earth.
- The author published a list of references in the story.
- The framing story was borrowed from P. G. Wodehouse's stories about the "Oldest Member".
- The narrator recalls Watson's stories about Holmes' "excursion across the moors" (The Hound of the Baskervilles) and his "wrestling match on a precipice" (The Final Problem). He also mentions Holmes' assistance to "Popes" (All-Consuming Fire) and an address in Belgravia (A Scandal in Belgravia).
- The hypothetical about a man named Reginald who served kippers was a reference to Wodehouse's character Jeeves.
- As noted in the story itself, Ruritania and King Rudolf originated from The Prisoner of Zenda.
- The men in the British Museum's Select Manuscript Room – the startled gentleman who spilled his papers, and the stout man who helped collect them – are Dunning and Karswell from M.R. James' Casting the Runes.
- The account of the Martian invasion of Earth is designed to be consistent with H. G. Wells's The War of the Worlds and Simon Bucher-Jones' Charles Dickens' Martian Notes.
- Holmes' comment about "continental orchestra" is a reference to George Bernard Shaw's complaints about the differences between how British and continental European orchestras tuned their instruments.
- The mentions of "squamous cephalopodic beasts" and "non-Euclidean geometry" are references to H. P. Lovecraft's work.
- Moriarty's The Dynamics of an Asteroid was first mentioned in The Valley of Fear.
- The "mock turtle soup and dodos' egg" are a reference to the novel Alice in Wonderland.
- History remembered the Martian embassy as being burned down in the siege of Sidney Street. The siege was mentioned and compared to the Holmes novel The Red-Headed League in Ronald Knox's essay Studies in the Literature of Sherlock Holmes, which first applied the idea of "canon" to works of fiction.
- The phrase "every trace of romance" was intended to be a reference to Lawrence Miles' novel Dead Romance.
- Tom dreams of demons trapped in pyramids. (TV: Pyramids of Mars, AUDIO: The Judgment of Sutekh)
- Sherlock Holmes aided a Pope in PROSE: All-Consuming Fire.
- James Moriarty wrote the book On the Dynamics of the Asteroid. (PROSE: The Death of Art)
- Moriarty's Theory of relativity was later attributed to Albert Einstein. (TV: Four to Doomsday, The Last Sontaran, et al.)
Community content is available under CC-BY-SA unless otherwise noted.