In Boston, Gus Stove is paid to kill Senator Barton Hale during the unveiling of a monument. The murder succeeds but, when the balance is paid, Gus understands firsthand that the matter is much more complicated than expected. Everything will be resolved in Concord, a town not far from Boston, where he and Ken Parker (agent of the "National") will find themselves side by side working in the rich house of a banker.
Ken, agent of the "National agency of investigation", is infiltrated among the workers of the textile factory "J. Troust & Co." tasked with identifying a union member. Soon, faced with the living conditions of the workers, Ken will understand who to side with...
Ken, seriously wounded in the back by a bullet fired during a workers' demonstration (see previous story), is treated by a gang of street kids. But is it possible to remain indifferent to the bounty hanging on the head of their client?