Answer:
That Captain Torres knows the barber is a revolutionary describes the story's main instance of irony.
Step-by-step explanation:
The story "Just lather, that's all" by Hernando Tellez, has a constant sense of iron since the two characters are faced to each other all the story and the barber has an inner conflict about killing the Captain since he is a revolutionary man and the Captain has done a lot of things against people, and the irony is that the Captain knew the truth all the time and wanted to see if the barber would dare to kill him.