The battle goes badly for the defenders of Gondor. The city gates are breached by Grond, the great battering ram forged in Mordor for just this purpose. The gates of Gondor shattered, the Lord of the Nazgûl commences his triumphant entry into the city. Only Gandalf comes to stand, alone, in the gap. But even Gandalf doesn't seem to be enough. Defeat has come. All seems lost...
In rode the Lord of the Nazgûl. A great black shape against the fires beyond he loomed up, grown to a vast menace of despair. In rode the Lord of the Nazgûl, under the archway that no enemy ever yet had passed, and all fled before his face.
All save one. There waiting, silent and still in the space before the Gate, sat Gandalf upon Shadowfax: Shadowfax who alone among the free horses of the earth endured the terror, unmoving, steadfast as a graven image in Rath Dínen.
"You cannot enter here," said Gandalf, and the huge shadow halted. "Go back to the abyss prepared for you! Go back! Fall into the nothingness that awaits you and your Master. Go!"
The Black Rider flung back his hood, and behold! he had a kingly crown; and yet upon no head visible was it set. The red fires shone between it and the mantled shoulders vast and dark. From a mouth unseen there came a deadly laughter.
"Old fool!" he said. "Old fool! This is my hour. Do you not know Death when you see it? Die now and curse in vain!" And with that he lifted high his sword and flames ran down the blade.
And in that very moment, away behind in some courtyard of the city, a cock crowed. Shrill and clear he crowed, recking nothing of war nor of wizardry, welcoming only the morning that in the sky far above the shadows of death was coming with the dawn.
And as if in answer there came from far away another note. Horns, horns, horns, in dark Mindolluin's sides they dimly echoed. Great horns of the north wildly blowing. Rohan had come at last.
It's a moment that gives you chills, a dramatic highlight of the book. The cock crowing. Dawn breaking. The horns blowing. Rohan comes at last.
In his essay "On Fairy Stories" Tolkien describes what he calls the eucatastrophe, "the good catastrophe," the experience of "sudden miraculous grace." In The Hobbit the good catastrophe comes when Bilbo shouts, "The eagles are coming!" The eagles will also come in The Lord of the Rings. But the definitive good catastrophe in The Lord of the Rings, in my estimation, are the words "Rohan had come at last."
The eucatastrophe is what makes the fairy story a religious story, what makes The Lord of the Rings a religious story. The eucatastrophe is what keeps the drama from becoming a tragedy, what keeps the metaphysics of the narrative from tipping into nihilism and terminal defeat. You have to believe in miracles, you have to believe in grace.
At the heart of the Christian story is our eucatastrophe: the resurrection of Jesus. Easter Sunday is "sudden miraculous grace," victory snatched from the jaws of defeat, life triumphing over death, hope defeating despair, and meaning conquering nihilism. The shadows of death scattered by the coming dawn. We live with the sound of the horns ringing in our ears.
