This is a popular question to ask because O'Connor has constructed "Guests of the Nation" in episodes that correspond to literary function. The first episode is, of course, the exposition in which O'Connor introduces characters and then establishes their interactions with each other, showing not only how the Irish rebels act with each other but also how the rebels act with the English prisoners.
The second episode develops the complication. The officer in charge keeps his distance from the others and shows no friendliness toward the English prisoners. The other two rebels, Bonaparte and Noble, are informed that the English soldiers are no longer prisoners; they are now hostages and will be executed in retaliation if the British forces execute any of their Irish rebel prisoners. This news is distressing to Bonaparte and Nobel; they can no longer relate with ease to the prisoners and can't sleep at night.
The third episode is rising action. Bonaparte and Noble get the report they have been dreading; the British have executed four Irish rebels, one of whom was a sixteen-year-old boy. Donovan gives orders that the British hostages, Hawkins and Belcher, will be executed by Bonaparte and Noble in the woods.
Episode four comprises both the climax and the falling action. Donovan and Bonaparte take the hostages through the woods to a bog. Donovan tells them that there is to be no transfer but they are to be executed. The theme of duty and responsibility arises while Hawkins tries to talk Donovan out of fulfilling his orders. Hawkins is shot. Belcher sees Hawkins is still alive and asks Bonaparte to shoot him a second time. Then Belcher joins Hawkins fate.
The falling point is when they must dig graves for the men who are now dead. The falling action follows when the rebels return to the cottage. The old woman of the cottage who has been with them all through the story falls to her knees in prayer when she realizes what has been done; Noble joins her in prayer on his knees.
Since this is Bonaparte's narrative and a story about his experience, the resolution occurs when Bonaparte goes into the dark night, looks at the dark sky and feels small, lost and alone. He ends his narrative by saying he could not think about things, like duty and personal responsibility, the same way as he did before.