Toronto: McLeod & Allen, 1909. Green ribbed cloth lettered in white. [8], 373, [3] pp + frontispiece with tissue guard and four other colour plates. Ink name on front free endpaper, front cover has part of "M" in "Mary" flaked away, one small light spot; else a VG+ tight and unworn copy. Her second crime novel in the scarce Canadian issue, made from sheets of the 1909 US (Bobbs-Merrill) first editon. Barzun and Taylor (#1863) considered it her masterpiece in the genre. Washington, D.C. setting.; Octavo