The speaker comes across a dead fox on a morning that already feels heavy, the morning after "the night we were forced to say good-bye." The poem never says who or what was lost, so that grief hangs in the background and colours everything. The fox becomes a place to put it.
Most of the poem is questions. Was the fox hunted, hit by a car, poisoned, or just old? Did it die quickly or slowly? The speaker can't know, and the piling-up of guesses shows how much they want the death to mean something, or at least to have been gentle. The fox is described with respect: "golden," "wise and wild," a creature that once ruled a "kingdom" now taken over by park runners.
The mood is tender, sad and a little angry, with a rough aside here and there. The ending is quiet and practical: the fox lies waiting, and someone will have to find it a place.