Careless Fritzi, the wife of a much older professor, has secretly been meeting with the unmarried Baron von Burghammer. Fritzi's husband finds out about the affair. Leoni, Fritzi's sister, pretends to be Burghammer's lover to spare her sister. Burghammer then falls head over heels for the brave woman.
Mamsie catches Lulu making a mess of the kitchen, so she punishes Lulu. When Lulu asks, "How do you know that I made this mess?", the maid says sarcastically, "A little bird told me!" Angered that the bird outside her home snitched to the family's maid, Lulu goes after the bird with her slingshot.
Mukta and Anand are childhood friends and love each other. But Mukta belongs to higher social class than Anand and her family wants to arrange her marriage with Jawahar, son of a rich man.
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.
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.
In Madrid, Spain, at the end of the 19th century, the young and reckless Basilio seems to be the only person who perceives the spectral presence of Professor Robinsón de Mantua, who begs him to take care of his niece Inés, because she is in grave danger.
Sgt. Rusty Curtis of the U.S. Cavalry is unhappy about the Army's plan to replace horses with tanks so, after a medical discharge, he tries to buy his old military mount Sireson.
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.