- Merlin's prediction about Vortigern's walls was right: they'd crashed down again. The foreman of the project swears they were building on solid rock.
- The priests are quaking in their boots. They know that if Merlin can pull this off and prove them wrong, their heads will roll.
- Merlin examines the site of the fallen wall and uses his engineer's brain to make some educated conclusions. This isn't magic—there's something amiss under the ground.
- But Merlin decides to play up the supernatural side of things by raising his arms to the setting sun. You know, to make it look like some kind of magic ritual.
- Again, it's excellent timing: the sun sinks as if on cue. It also helps him to see something from his past: he remembers that the road below him leads to the mines that he and Cerdic had explored.
- Merlin continues with the ritual gestures, all for Vortigern and the men around him. He's pretending to locate something that he already knows is there under the earth.
- Then Merlin leads everyone to the entrance of the old mine. He tells Vortigern that there's a magic beast that eats at the base of his walls and keeps them from standing.
- When they all enter the mine, it occurs to Merlin that this is the scene from the crystal cave that he had many years ago as a boy.
- Merlin shows Vortigern a rock at the bottom of a subterranean pool that's shaped like a dragon. There's his beast. He needs to drain the pool to make the walls stand.
- But the torches shed light on the pool and send it flashing all around Merlin. It's like the crystal cave on demand. And sure enough, a powerful vision overcomes him.
- And it's a painful vision. Merlin falls to the ground in pain and thinks that Vortigern and his men are actually killing him to get his blood for the foundation.
- Merlin sees a red dragon chasing down its prey, then an army with banners, then a huge comet. And then, he heroically passes out.