Two young subterranean laborers converse in an ancient, shadowy network of galleries beneath a sunny city. Through a duologue they reveal daily dangers of their work, memories of accidents, and tender affection, as the girl sings hymns and breathes rare air that suggests an imagined spring above. Scenes focus on sensory contrasts between dim, mechanical passages and a pale light from a flue, combining practical details of mining-like labor with longing for safety, beauty, and the unknown realm of light beyond their underground world.