Wilfred Owen's poem uses the perspective of a soul looking down after death to depict the destruction of World War I. The soul witnesses emaciated caterpillars slowly moving across barbed wire and infecting the land, representing soldiers. As the caterpillars consume each other, the soul is filled with terror over what it means. Death then shows the soul a severed caterpillar whose feet resemble many men and head resembles the soul's, symbolizing Owen's own death in the war.