The Hammering Man by William MacHarg

“The Hammering Man” (also published as “Decidedly Odd”) is part of Edwin Balmer and William B. MacHarg’s Luther Trant series, a 12-story sequence of mysteries featuring a detective armed with psychoanalysis. (It doesn’t hurt that Trant also has a keen analytical mind and can unravel the greatest of puzzles). The series began in 1909 in Hampton’s Magazine and was collected as The Achievements of Luther Trant in late 1910. In "The Hammering Man," Trent must unravel the puzzle of a advertisement with ties to Russia and a cypher with a hidden clue.