Dark River Rising by Roger Johns Minotaur Books/St. Martins Publishing Group, $26.99, 2936 pages, ISBN 978-1-250-11009-1 The Mysterious Book Report is always on the lookout for promising debut authors with unique protagonists and interesting points of view, that are set in unusual places which are all wrapped up in an original and compelling plot. This is such a one, an outstanding new murder mystery that takes place down south,