Having been wounded, the sniper concocts a plan to make his opponent think that he has been killed. He puts his cap on the muzzle of his rifle and shows it above the parapet. A bullet is shot through the center of the cap immediately, and the sniper on the other rooftop, letting his guard down, stands up so that the sniper can get a clear shot at him.
Three distinct ironies arise from this circumstance, the last being by far the greatest. In the first place, the sniper carries through his plan and shoots the man, but he feels none of the elation and relief he might have expected. His success brings him only self-loathing and nausea. The second irony is that the sniper fails to learn from the example of the man he has killed. When he goes down to the street, he relaxes his guard, as he believes that his enemies are dead. He is rapidly corrected by a volley of machine-gun fire.
The final and most important irony comes at the very end of the story. The sniper finds that the man he has regarded as an enemy throughout the conflict is, in fact, his brother. This is a surprise, although it was foreshadowed by his nauseated reaction after shooting the man.