Indianapolis: Bobbs- Merril Co., (1913). First edition. Color illustrations by Andre Castaigne and black-and-white illustrations by Arthur William Brown. MacGrath's 8th mystery, the basis for the 1921 silent film "Not Guilty." Fine, bright copy with just a hint of soiling on top edge; in bright, good or better, full wrap-around illustrated dust jacket (including flaps) with chipping on edges not affecting any lettering, and closed tear evident on spine which has been backed with clear archival tape.