Edgar Wallace 
Clue Of The Silver Key 

This thrilling murder mystery features some veritable characters: inventor and heir-at-law Dick Allenby, and banker and speculator Leo Moran. Add Dornford, Hennessey and the actress Mary Lane, and Washington Wirth who gives parties and loves flattery. Hervey Lyne, Binny and the indomitable Surefoot Smith. Of them all only Tickler is innocent. Leaving gala night at the Litigation Club, Dick and Surefoot are discussing guns…but there before them a cab has been left in the middle of the road. The man inside has been shot.