"The Case of the Wavy Black Dagger"

by Steve Perry
originally published Shadows Over Baker Street, Ballantine, 2003

Sherlock Holmes is lounging in his study one night, when a shadowy figure attempts to sneak up on him.  Of course, you can't sneak up on Holmes.

Holmes and his intruder, a lovely Balinese woman, engage in some challenging banter.  It seems she's the priestess of a Balinese cult, come to retrieve an ornamental dagger stolen from the cult, which has come into Holmes possession.  The dagger is needed to slay a monster called the Black Naga, one of the Old Ones, with which Holmes is, of course, familiar. 

Holmes, impressed with her honesty and more than a bit smitten, hands over the dagger.
  
A trifle, though entertainingly written.  The title strikes me as painfully silly.