Purgatory Ridge By William Kent Krueger. Not far from Aurora, Minnesota lies an ancient expanse of great white pines, sacred to the Anishinaabe tribe. When an explosion kills the night watchman at wealthy industrialist Karl Lindstrom's nearby lumber mill, it's obvious where suspicion will fall. This book will pull you in from the first page and hold you fast until the satisfying correct wrap-up on the last page! THIRD IN THE CORK O'CONNOR MYSTERY SERIES.