The Listeners

By Walter de la Mare

"Is there anybody there?" said the Traveler,
          Knocking on the moonlit door;
And his horse in the silence champed the grasses
          Of the forest's ferny floor;
And a bird flew up out of the turret,
          Above the Traveler's head :
And he smote upon the door again a second time;
          "Is there anybody there?" he said.
But no one descended to the Traveler;
          No head from the leaf-fringed sill
Leaned over and looked into his grey eyes,
          Where he stood perplexed and still.
But only a host of phantom listeners
          That dwelt in the lone house then
Stood listening in the quiet of the moonlight
          To that voice from the world of men:
Stood thronging the faint moonbeams on the dark 
                    stair,
          That goes down to the empty hall,
Hearkening in an air stirred and shaken
          By the lonely Traveler's call.
And he felt in his heart their strangeness
          Their stillness answering his cry,
While his horse moved, cropping the dark turf,
          'Neath the starred and leafy sky;
For he suddenly smote on the door, even
          Louder and lifted his head:-- 
"Tell them I came, and no one answered,
          That I kept my word," he said.
Never the least stir made the listeners,
          Though every word he spake
Fell echoing through the shadowiness of the still
                    house
          From the one man left awake:
Ay, they heard his foot upon the stirrup,
          And the sound of iron on the stone,
And how the silence surged softly backward,
          When the plunging hoofs were gone.
          

What does this mean? I can’t stop thinking about it! Who are the listeners? Why can’t they answer? Who is this man? What promise did he make? Why was it so important that he came to the house? Am I missing something?