If you are going to change anything, I think the Prologue is absolutely the wrong place to do it. It is quite possibly (and in my mind, is definitely) the best chapter in any of the books. You incorporate small bits from the "flashback" scene that opens it into Kellhus' journey out of Ishual.
How do you film it?
Opens with a pull back of Ishual's curtain wall, sprawling, ornate, but clearly secreted away in the glaciers and abandoned. Cut to Anasûrimbor Ganrelka II's party, haggard (be sure to show the ornate five Knights of Trysë, close by Ganrelka clearly worried for his safety); the wind howls, the look on their faces says "was that the wind, or a horn?" They look ahead to Ishual in the distance. Cut to Ganrelka is a bed, clearly dying of plague, cut to the distraught faces of those who were in the party shown before, as tears stream down his face. Cut to a cold morning, foggy, his bier set up to be lit in the pyre. Show wolves eyes gleaming in the firelight. Show the rest of the party somber, no singing, just looking down, then back to the walls of Ishual, numerous sentries posted, intent on the horizon.
Cut to Ganrelka’s concubine and her daughter showing the same signs of sickness. Show bodies being heaped up, show the same place, same sentries, only 1/4 the number now. Show one of the few remaining begins to cough. Cut to the five Knights of Trysë in beds, dying of the plague at various stages, from dead to near dead. Cut to the Grand Vizier "his golden robes stained bloody by his bowel, lay sprawled across his sorcerous texts." Cut to Ganrelka’s uncle swinging from the rope he hanged himself with. Cut to The Queen, in a bed covering in blood, flies buzz yet she simply stares out, blankly, to a tapestry of the Anasûrimbor coat-of-arms. Pan out to show Ganrelka’s bastard son looking in on her, a blank and lost look, but not sad, she isn't his mother and his father is already gone.
Cut to the boy searching the halls. Emtpy rooms, bodies in various states of decay. Then, he finds the Bardic Priest and focus on his strange look. Show the boy fleeing. Show the Bardic Priest looking for him, calling to him. Cut to him finding him, huddled in a corner, "He caressed first his cheek and then his thigh. “Forgive me,” he muttered over and over, but tears fell only from his blind eye. “There are no crimes,” he mumbled afterward, “when no one is left alive.”"
Cut to the same wall from before, no sentries now, one dead and rotting in the background. The Bardic Priest, drunk, stumbling after the boy. Then, as he nears the walls edge, the boy is behind him. A stone-faced look and a push. Show the broken body of the Bardic Priest far below.
Cut to the same wall, clearly winter has come in force, show snow on the trees, ice covers the walls. The boy sits, in his father's furs, blood and all, and listens as wolves bey, he softly sings "mother’s songs" while Gnawing on hardtack. Cut to him "fly[ing] through the courtyards, answering the wolves with Kûniüric war cries, brandishing weapons that staggered him with their weight. And once in a while, his eyes wide with hope and superstitious dread, he would poke the dead with his father’s sword."
Cut to the end of winter, show the thawing by the treetops, from that same wall again. The boy no longer sit in furs. The sun is rising and the boy is started to hear voices from down below. Show the Dunyain refugees, "fearsome—feral, like a wolf people." The boy runs. Cut to them fashioning ropes and climbing the walls of Ishual. Cut to them finding the boy, huddled in the midst of the now bone dry corpses with his father sword. “We are Dûnyain, child. What reason could you have to fear us?” But the boy clutched his father’s sword, crying, “So long as men live, there are crimes!” The man’s eyes filled with wonder. “No, child,” he said. “Only so long as men are deceived.” For a moment, the young Anasûrimbor could only stare at him. Then solemnly, he set aside his father’s sword and took the stranger’s hand. “I was a prince,” he mumbled."
Cut to Dûnyain scrubbing the walls, chiseling off the runes, burning the sorcerers books, etc. Pan out, far and wide, show the remoteness of Ishual, how hard it would be to see from far. Words, 2,000 years later, and the "present" date.
A hazy vision of Shimeh, clearly a dream, the sounds of battle distant and muted. A cut to each dreamer, asleep, and back to aspects of the dream. Visions of dead near a sea, a desert oasis, etc. A serpent voice, “Send to me my son.” Show each awaken, startled.
Cut to them meating in the darkness of Thousand Thousand Halls. They look, wearily to each other, "This must end."
And so on. It wouldn't be hard and I think it would make for a great opening to the show. Lots there for water cooler talk the next day. Plenty more to connect it to the next part, with Kellhus walking from Ishual, in the same path that Ganrelka had walk to it. Kellhus' look back, show that same wall, where the boy had always been, to show the Pragma who would kill themselves. It would all come together, I'm not even talented but the source material is so good it easy to fashion things out of it.
