The Duel of Shadows: The Extraordinary Cases of Barnabas Hildreth

Author: Vincent Cornier

Publisher: Crippen & Landru

Publication Date: August 2011

Cornier may be a bit better known in weird-fiction circles than in crime/mystery, but in 1948 Fred Dannay said that the stories in this book formed "One of the great series of modern detective stories."  They were originally published in the UK magazine Pearson's in the 1940s. Edited by Mike Ashley.