I need to know the use/effects of irony in "Just Lather, That's All." Anyone have any clues? Any suggestions would be greatly appreciated.

In this short story we meet a Barber who is also a secret revolutionary. His enemy comes in for a shave and through this first person narration from the Barber, we find out about Captain Torres, who has killed and tortured many of the revolutionaries. The Barber shaves Torres as he contemplates cutting his throat while he is in the barber's chair, but he cannot go through with it. However, ironically, the shave actually rejuvenates Torres and makes him even look younger, rather than harm him.The most important irony of all, however, comes at the end of the story when Torres leaves unharmed and tells the Barber that everyone had thought that the Barber would kill him, but murder is a difficult task. Thus, the irony lies in the fact that all along the Captain knew the Barber wished to kill him and knew he was a revolutionary. Irony is responsible for the twist at the end which makes this a good story!