"Sweetheart of the Song Tra Bong" culminates in a rich, visceral scene in which Mary Anne sits in the Special Forces Hootch chanting in a foreign language. The passage in which O'Brien describes this scene—by way of Rat Kiley's voice—contains hyperbole, imagery, and simile. These literary devices come together to reinforce the strangeness of the scene and the mystery of Mary Anne's transformation.
At first, Rat Kiley stands outside the hootch with Eddie Diamond and Mark Fossie. At this time, the imagery is mainly auditory, as the men listen to Mary Anne's high pitched chanting and the accompanying music. When Fossie slips inside, Kiley and Diamond follow. The imagery then revolves around the sense of smell:
There was a topmost scent of joss sticks and incense, like the fumes of some exotic smokehouse, but beneath the smoke lay a deeper and much more powerful stench. Impossible to describe, Rat said. It paralyzed your lungs. Thick and numbing, like an animal’s den, a mix of blood and scorched hair and excrement and the sweet-sour odor of moldering flesh—the stink of the kill.
This part of the passage also contains hyperbole, as Kiley claims the underlying scent is "impossible to describe" and that it "paralyzed your lungs." He nevertheless makes an attempt, using a simile that likens it to an animal's den. Besides featuring many layers of figurative language, the passage contains many layers of olfactory imagery: joss sticks and incense like fumes of an exotic smokehouse, a thick and numbing stench like a mix of blood and scorched hair and excrement and moldering flesh. Through this overpowering imagery, O'Brien gives the reader an eerie and disconcerted feeling. As the scene develops further, it becomes clear where some of the more fleshly smells come from—the origin of the "the stink of the kill":
On a post at the rear of the hootch was the decayed head of a large black leopard; strips of yellow-brown skin dangled from the overhead rafters. And bones. Stacks of bones—all kinds.
This passage feels hyperbolic, and the narrator seems to push the details as far as possible. Not only does the hootch contain "all kinds" of bones, Mary Anne is even wearing a necklace of human tongues. Despite these extreme elements, Kiley insists that everything he has told until this point "is from personal experience, the exact truth."
For the reader, it's worth asking what O'Brien is suggesting through some of the more severe aspects of Mary Anne's transformation. At the beginning of the story, he makes it quite evident that coming to Vietnam is the reason why Mary Anne changes. This may simply be because Mary Anne has the chance to travel far from home for the first time. It may also be because she is captivated by fighting, weapons, covert operations, and being granted entry into a masculine sphere. However, O'Brien seems to relate her character development to a certain exoticization of Vietnam, suggesting that there is something supernatural about the landscape and culture that sets her off.