In its original Golden Age 1940’s edition, the Enchanted Dagger took place in Washington D.C.  I loved the idea of a guy running around D.C. with a magic knife that paralyzes people and makes them tell the truth.   A den of devious politicians would be utterly terrified by a creep like that!  My take took off from there.  I changed the location from Washington to Great City (the home base of a 1930’s pulp magazine character called The Moon Man who I’d written about in an earlier short story), mostly so I could draw a more dramatic ‘Fritz Langian’ skyline.