Equal parts daring and prone to disaster, B. M. Bowerâs beloved hero with a heart of gold, Casey Ryan, is at it again in âThe Trail of the White Muleâ. Whether heâs veering through traffic at high speed in the boomtown of Los Angeles or pursuing bootleggers in the country, Ryan always seems to find himself in the middle of a maelstrom. He willingly got involved with moonshiners and transporting booze â but lucked out in the end by helping the authorities. âThe Trail of the White Muleâ was written in the year 1922 by B.M. Bower. This book is one of the most popular novels of B.M. Bower, and has been translated into several other languages around the world.