de Brune, Aiden: The Dagger and Cord (1927); V1; 14 Oct 2019
 

When the dead body of an unknown young woman is found in a disused shop in Sydney by property broker Roy Onslay and real estate agent Mark Mansell, a complex web of frame-up, scheming and double dealing erupts, Involved is a enigmatic and elusive property heiress and her secretary Rene Wesche; wealthy property speculator Sam Kearney, shady character Basil Holt; and Antonio Cavalli and his secret society preying on the Italian community.

De Brune's most complex serial, and the longest. It was also published in book form by Cornstalk Press in 1927, and serialised in several newspapers. I have added the original dust wrapper image as a frontispiece.

Fun fact: the derelict shop is in a lane named "Peyton Place".