After Mike witnesses a barefoot bank robber who got away in a hail of bullets, an iron-fisted longshoreman union boss hires Mike to find the killer of his granddaughter, a loose-morals woman who slept with both sides of a labor war. A second murder confuses his case, but the bank robbery connects somehow with the murder. Even though directed not to pry into union affairs, every lead takes Mike there, in ever deeper danger, until he's shanghaied in a shipping container en route to Tokyo. His initial theory doesn't fit the limited evidence. Mike is tempted by three different women, one of whom comes on to Molly as well. Once again solo as Rick is mostly retired and Molly puts her lack of reflexes in a desk job downtown. Mike and the police see things as wrapped up, but are they? Set in Portland, Oregon in 1970 Dark Union is number 11 in the series.