New York: Robert J. Shores Corporation, 1918. Dark blue cloth stamped in red and blind. 336, [4, ads] pp + four plates. Lower outer corner of front cover rounded from wear; text paper a bit toned, page edges yellowed; else a VG tight copy, no owner nam es. Author's first of two crime novels noted by Hubin p. 383. WWI, German spies, wireless, a super explosive. Uncommon book.