Upon hearing about his regiment's surprising victory, Henry feels as guilty as a criminal. He resents the "stupidity" of his fellow soldiers who stayed to fight. On the contrary, Henry feels he had assessed the situation rationally and, by running, saved the army at least one of its soldiers. But he thinks his regiment won't understand that and will hate him.
To protect himself from feeling like a coward, Henry tells himself that his fellow soldiers' courage was in fact stupidity. Ironically, later on Henry will think of the exact same behavior as courageous when he stands his ground and fights.
Confused and mentally anguished, Henry wanders into the thick woods. He throws a pine cone at a squirrel who runs off. Henry is pleased to interpret this as a sign: he reasons that it's nature's law to run from danger. Henry feels in harmony with Nature.
To deal with his guilt, Henry interprets the squirrel incident as proof of Nature's sympathy. He has a deep need for approval from somewhere, and his mind keeps searching for it.
Henry pushes deeper into the silent woods to a grove with high branches that resembles a chapel. In this "chapel," Henry is horrified to discover a Union soldier's corpse. Ants are running over its discolored face and swarming up to its dull eyes, and one carries off a piece of flesh. Henry screams, but stays and stares into the dead man's eyes. He slowly paces backward, afraid that the corpse will jump up or call after him, and then he flees in terror.
The silence and "chapel" imagery suggest a religious encounter, but with death rather than life. Whatever the solider did in battle doesn't matter anymore—now he's just dead. The ant-covered corpse represents Nature's indifference to human concerns.