By Harlan Halsey. Introduction by Henry Stewart. From the back cover: "During the craze for cheap crime fiction in the late nineteenth century, Harlan Halsey wrote more than a hundred potboilers as Old Sleuth, a brilliant and gentlemanly master of disguise." Not strictly speaking my "lane" here at ExB, but this iteration is "presented" by the author of True Crime Bay Ridge -- and this copy’s a nice one, only the mildest edgewear from storage, and bright and neat as a pin inside.