Answer :
The traveler is within a deep dark forest along with his horse.The traveler visits a castle and calls out but no one responds to him as they(phantom listeners) hear his fervent call.The bird that flies out of the castle signifies that no one is living in the castle except for birds of the sky.The moonlight is reflecting on the eyes of the traveler suggestion that there's no other light.It is expressed through "grey eyes".He stands 'perplexed and still' as no one answers his call and his voice is the only voice from the world of men.