After witnessing a barefoot bank robber two blocks from his office, an iron-fisted boss who ran the longshoreman's union since the 1930s hires Mike to find the killer of his granddaughter. The victim was a loose-morals woman who slept with both sides of a labor war. The victim's sister was a client's secretary in his prior case, and Mike is drawn to her petite seductiveness and unabashed claims on him. Efforts to get information inside the union are fraught with danger and difficulty. His client is adamant Mike is not to pry into union affairs, but every lead takes Mike there, in ever deeper danger, until he's shanghaied in a shipping container en route to Tokyo. Throughout the case Mike is tempted by three different women, one of whom comes on to Molly as well. Once again Mike goes solo as Rick is mostly retired and Molly decides her lack of reflexes is a field liability. She takes a job with brother in law's insurance firm. 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.