A young Eastern lawyer, seriously injured in a stage holdup, secures the help of Hoppy, California and Jimmy in completing his mission to his woman cousin's ranch in Texas.
With a plot line mostly lifted from 1941's "White Eagle", Columbia's 24th serial (following "The Desert Hawk-1944" and ahead of 1945's "Brenda Starr, Reporter"), "Black Arrow" finds carpet-baggers Jake Jackson and Buck Sherman arriving in Blue Mesa in search of gold.
Dan Stanton and Condon are foreclosing on a group of ranchers in order to gain a land-monopoly. They have one of the ranchers, whose property supplies the others with water, killed.
Henny Brown, talent scout for the Margaret Ames Film Agency in Hollywood, mistakes Broadway show understudies Judy and Marian, for stars Betty and Eileen, and signs them up for movies.
In this entry in the MGM "Crime Does Not Pay" series young Frank Davis, dropping out of school and joining a small-time hoodlum gang, finds out that leading a life of crime is not all he thought it would be.
Muggs and Glimpy, two East Side Kids in the army, return to their neighborhood, supposedly on furlough; actually, Muggs has been honorably discharged with a physical defect, but he tells no one of this.