Professional killer Bus Crow is hired by cattlemen to eliminate squatters. When Marshal Sam Rochelle is sent to investigate, saloon owner Hallie has to be a reluctant witness.
In 1918, Elizabeth MacDonald learns that her husband, John Andrew, has been killed in the war. Elizabeth bears John's son and eventually marries her kindly boss. Unknown to her, John has survived but is horribly disfigured and remains in Europe. Years later, on the eve of World War II, Elizabeth refuses to agree to her son's request to enlist and is stunned when an eerily familiar stranger named Kessler arrives from abroad and becomes involved.
After a rare gem is stolen from an exhibition at a posh hotel, Inspector Farraday decides to recruit former thief Boston Blackie to find the stone. Along with his assistant, "The Runt", Blackie focuses his investigation on the hotel manager, George Daley, and his sister, Eileen. Through disguises and ruses, Blackie and the Runt try to trick their way to discovering the thieves.