The story opens with the protagonist, known as "the lieutenant," surrounded by "Corporals and other representatives of the grimy and hot-throated men" (paragraph 1, sentence 2), on the front lines of a battlefield during the American Civil War. He is divvying up coffee rations into piles "astoundingly equal in size" when suddenly he is shot in the arm (paragraph 2, sentence 2). At first, no one seems to understand what has happened. He and the rest of the menturn to the woods, "where now were many puffs of white smoke," indicating gunfire (paragraph 3, sentence 2). Still no one moves, until the lieutenant clumsily attempts to re-sheathe his sword with his uninjured left hand. Then some of the onlookers offer to assist and at the same time seem weary of him, his status in their eyes having changed with his injury.

The lieutenant turns to head back to the rear of the front to seek treatment. Along the way, he sees many of the things that are generally hidden from the men on the front lines. He sees the greater movements of his brothers in arms, as well as the general and his staff. He pauses to watch, “until all detail of it were lost, save the figures of the riders, which rose and fell and waved lashes over the black mass” (paragraph 13, sentence 1).

He then comes across a group of “stragglers” who direct him to the hospital, and he is struck by the idea that they know a lot more from their position in the rear than he could, not just of the layout of the camp but also of the generals and how the battle is going (paragraph 15, sentence 1). A little later, an officer in a brigade near the rear scolds the lieutenant for not having tied a bandage over the wound and helps him do it.

Finally, he comes to the hospital and sees a chaotic scene, with two ambulances who have “interlocked wheels” (paragraph 17, sentence 3) and “[a]n interminable crowd of bandaged men […] coming and going” (paragraph 17, sentence 5). He also sees an ashen-faced man leaning against a tree and has to fight the urge to “rush forward and inform him that he was dying” (paragraph 17, sentence 9).

In the final full scene of the story, a surgeon sees the lieutenant as he is passing and stops to attend to his wound, saying that the officer who bandaged it is a “mutton-head” (paragraph 18, sentence 6). The surgeon’s tone and manner suggest to the lieutenant that he is contemptuous of the injured man, which makes the lieutenant resentful, and he resists being escorted into the hospital tent, fearing he will lose the arm. The surgeon assures him he will not amputate.

The last paragraph jumps ahead in the narrative, and tells us the lieutenant did in fact lose the arm, and he is greeted returning home by “his sisters, his mother, his wife,” (paragraph 24, sentence 2), and the lieutenant’s only reply is “Oh well […] don’t suppose it matters so much as all that” (paragraph 24, sentence 3).