Near the beginning of the story, when the narrator is orienting readers to Druse’s location at the top of a cliff, they use a simile, as seen in the following passage:
Druse turned his head and looked through the deeps of air downward, as from the surface to the bottom of a translucent sea. He saw creeping across the green meadow a sinuous line of figures of men and horses — some foolish commander was permitting the soldiers of his escort to water their beasts in the open, in plain view from a dozen summits!
The simile here compares the space between the cliff and the valley to the distance “from the surface to the bottom of a translucent sea.” This comparison helps readers understand the vastness of the valley, as well as how easily someone on the cliff’s edge could fall to their death (as the horseman goes on to do).
While the language in this passage is initially poetic—Druse is reveling in the vastness of this sea-like space—it quickly becomes pragmatic when Druse notices some of his fellow Union soldiers out in the open on the valley floor and worries about them being vulnerable to attack. That a commander is called “foolish” for coming out of hiding to grant his horses access to drinking water demonstrates the precarious and deadly nature of this situation.