How we cite our quotes: (Book.Chapter.Paragraph)
Quote #1
The cave was bigger than I had imagined. It stretched upwards further than I could see, and the floor was worn smooth. I had even been wrong about the crystals; the glimmer that reflected the torchlight came only from puddles on the floor, and a place on one wall where a thin slither of moisture betrayed a spring somewhere above. (I.7.40)
Merlin's having his first mind-bending experience in the crystal cave. He's actually seeing the mineshaft in Segontium, the one that he will so desperately need to find years from this moment, when he's prophesying for his life before Vortigern. Crucial point: Merlin doesn't necessarily know what he's seeing at first in his visions. It often takes years for them to come true.
Quote #2
The starlight struck the face of the stone where I had paused to wait, and something caught my eye, a shape rudely carved in the granite, and etched by the cold light like lampblack. An axe, two-headed. The standing stones stretched away from me into darkness like a march of giants. […] As I turned away I glanced at the axe again. It had vanished. (II.2.7)
Merlin has this freaky encounter on his first night in Brittany as he follows a wagon to Ambrosius. He doesn't understand the significance of the two-headed ax until later, when he learns that it is symbol for "the god." The freakiest part? The image of the two-headed ax appears only to him, and it disappears after he sees it. It's an early hint that Merlin has a great mystical purpose on earth.
Quote #3
The man saw me coming and turned his head, and I saw that nothing was needed. He was smiling, but his face in the starlight seemed curiously smooth and unhuman in its lack of expression. I could see no sign of stress or effort. His eyes were expressionless too, cold and dark, with no smile there. (II.3.24)
Merlin has a vision of the godly Mithras, who slaughters a white bull so that fertility can be restored to the earth. Merlin has no direct knowledge of this myth, though he'd seen depictions of Mithras back home in Wales. The vision marks Merlin out as someone special to this god, and it keeps him from being killed by an angry Uther.