In the futuristic London of another universe's 1895, a prominent visitor arrives at 221B Baker Street with an unsettling narrative.

Her Excellency Madam Enauheh hsh Hwúnhirh, the interstellar Alliance's  High Commissioner for Hearthworld Affairs, comes secretly to warn Sherlock Holmes and Doctor and Captain John Watson of an assassination—her own—though at the same time she claims that that event might not particularly matter. It falls to Earth's only consulting detective and his constant companion and confidant to lay bare the shadowy truths behind the threat against their visitor, and to prevent an assassination that (if it does succeed) will have effects much more far-reaching and severe than their client's mere death. 

The Adventure of the Lioness's Mane is a 12,000-word novelette and sequel story to the Holmes and Watson novel Sherlock Holmes and the Giant Rats of Sumatra III, currently in progress. This story originally appeared in a shorter version in Multiverse of Mystery: A Holmes and Watson Anthology, and is published here for the first time in its original longer form.