The Assassination Bureau has existed for decades (perhaps centuries) until Diana Rigg begins to investigate it. The high moral standing of the Bureau (only killing those who deserve it) is called into question by her. She puts out a contract for the Bureau to assassinate its leader on the eve of World War I.

Master gunslinger Sabata arrives in Hobsonville, a town completely owned by McIntock, a robber baron who is taxing the inhabitants for the cost of future improvements to the town. Or that's what McIntock says he'll do with the money...