Write a 50-word teaser on "The Sniper" by Liam O'Flaherty.

It is no easy thing to trim such a detailed and surprising story down to a mere fifty words. However, a good place to start would be to decide on the story's most important elements as well as how best to pique readers' interest in its content. The setting in 1920s Dublin seems significant in achieving an understanding of the conflict described in the story. We must identify the protagonist, as well: he is an unnamed Republican sniper looking to keep himself alive even as he strives to neutralize any enemy threat. Finally, the protagonist's happiness at his apparent success in shooting and killing an enemy sniper on another rooftop is followed by his immediate "remorse" as "the lust of battle died in him." This feeling seems to foreshadow his eventual recognition that he has shot and killed his own brother.
On the other hand, I would leave out a description of the tactical strategy the sniper employs after sustaining his own injury, as this is not really necessary for such a brief synopsis of the story. It is a teaser meant to tempt someone into reading it. Another good idea might be to not reveal that the dead man at the story's end is the sniper's brother. Instead, mention that it is someone with whom he has a very close relationship: their death will not only shock him, but will likely haunt him for the rest of his life. Then, someone who reads your teaser would probably be compelled to read the story in order to find out just who the sniper has shot.