This poem, which is not to be confused by Muir's other poem about horses entitled "The Horses," presents an image from the world of farming as the speaker looks at horses pulling a plough across a field. However, ironically, although this image would seem to demonstrate man's mastery over the horse and his dominance over nature as a whole, the speaker only views the horses as being symbols of power and strength that are not able to be tamed by man and are independent in their own right. He wonders why the horses that he sees "seem terrible, so wild and strange," and he sees in them a kind of "magic power" that is captured most strongly when they return home at dusk, and for one moment, the speaker sees before him mythological beasts instead of horses who overwhelm him with their power and presence:
They came, they seemed gigantic in the gloam
And warm and glowing with mysterious fire
That lit their smouldering bodies in the mire.
Their eyes as brilliant and as wide as the night
Gleamed with a cruel apocalyptic light.
Their manes the leaping ire of the wind
Lifted with rage invisible and blind.
Note the qualities that are associated with these horses through a series of similes and implied metaphors: they are linked with the "leaping ire of the wind" and a "rage invisible and blind," and they seem to burn with a "mysterious fire." However, by the end of the poem, the speaker, with sadness, comments on how this vision fades away, and he is left to "pine" the sight he experienced, and as a result is left diminished himself. The main theme of the poem seems to focus on the way in which man has domesticated nature, but yet how nature itself, symbolised in the form of the horses, still has immense power and might. Man, by the end of the poem, is shown to be diminished by its domestication of nature, and to be left the poorer as a result.