The Peacock of Jewels by Fergus Hume — Read

Considering that Marie was inexperienced in worldly matters, she acted with extraordinary foresight and determination. Few girls would have risked that journey to the Rotherhithe slum, or would have conducted the interview with Mother Slaig so discreetly. Certainly her lucky star was in the ascendant when she plunged into those malodorous depths, as she had been guarded from all peril by the various policemen; but her own diplomatic behavior had accomplished the impossible with the old harridan. Marie returned home with the full belief that Morad-Bakche was the guilty person, since he desired to obtain possession of the peacock, and he had been haunting the house wherein Baldwin Grison resided. That Sorley had held the bird-a fact vouched for by Alan-she believed was due to the machinations of Miss Grison, who evidently was working in concert with the Indian to ruin the man.

And Bakche's reward would be possession of the jewels, since Marie fancied the dead man's sister had possibly guessed the riddle of the ornament. If this was so, there was no need for either of the conspirators to retain possession of the peacock, since it had yielded up its secret.