I looked around. Rocks had fallen into the riverbed from the heights across from us, making fresh changes in the rapids. A crack had opened in the riverbed. That had dropped the bottom another thirty feet. The lake was booming down into the new channel, throwing up a fine, cool spray. Moharrin had a new waterfall.

“There was a shock?” I asked. I offered the flask to him, but he shook his head.

“More like a long shiver, but a hard one. Some trees fell.” There were shadows in Oswin’s blue eyes. It must have been a scary shock.

“Why didn’t you go? I must have been entranced for a while,” I said.

“Go back to see Nory try to get the axle fixed on that cart?” he inquired. “The smith’s apprentice might have done it—he’s sweet on her—but he left with the smith. She’ll be furious, which means she’ll be bullying someone else into fixing it. I’d offer, but I doubt she’d even let me try a second time. She knows I’d probably just botch it again. I feel bad I couldn’t get her and the kids a decent cart.”

“You do lots of other things for them,” I told him. “You give them a home.”

Oswin spat on the ground beside him. “It won’t do them much good if it and they get buried in ash and lava. What were you doing away from your body? I wouldn’t think gathering power would take so long.” He offered me some dried figs.

I ate those, too. “I was exploring the fault under the river on out to the sea.” I looked over at the granite marker nearby. It had fallen over. I called to it. Slowly, pulling against the soil, it straightened. I tugged on the surrounding rocks. They rolled into place, bracing the marker until it stood firm again.

Oswin swallowed hard. “I’m used to a bit more fuss when people work magic.”

I shrugged.

“Maybe you know the answer to this, since you’re the stone mage,” Oswin began. “What are they, these lines? Big and small? Tahar and Jayat don’t know what they are, apart from the fact that they carry power. They only know they can use them.” Oswin drew his knees up to his chest like a boy and wrapped his arms around them. His eyes were blazing with curiosity. “They never say where the power comes from, or why they find it in these places, and not in others. When the lines moved, Tahar and Jayat were at a complete loss. They couldn’t find new ones.”

“But that’s silly,” I told him. “Why didn’t they just do a spell for feeling power, and sweep across the ground? The big faults didn’t move far. They couldn’t. Look. The lines—they’re faults, or seams in the earth’s stone cloak. The faults reach down. Miles, some of them. Way below us, the world is full of molten rock—lava. Well, Luvo and my stone mage teachers call it magma inside the world, lava when it’s out in the air. It’s heat, it’s pressure—it would mash us flat in the blink of an eye—it’s light, it’s the elements that make up every stone, every mineral, every metal and every gem ever was.”

“How do you know?” Oswin asked me.

“What?” I was confused.

“How do you know that’s what’s in it?”

I blinked. “Well, when one of my teachers was called away, I sneaked a look at the books for the advanced students. But I would have known anyway, after this. I can feel them. The—the makings of gold, and iron, and sulfur. Like healer mages would know if a woman’s unborn baby is a boy or a girl or dead or a mage.”

Oswin shook his head. “I’m surprised you bother with us human beings at all. You must live in a dream world, if every stone and crystal speaks to you like that.”

He’d finally startled me. How could he know that, and him not a mage? “People are all right.” I sounded like a liar even to myself.

Oswin smiled at me. I wondered how much he saw, and how much he missed. Suddenly what Jayat had said, that Oswin fixed things without magic, made a lot more sense. “All people, or some people?” he asked.

“I don’t know. I haven’t met all people,” I replied. Maybe I should have let the volcano spirits squeeze me instead of escaping up to this.

I think he took pity on me. “You were telling me about what’s far below the surface stone,” he reminded me.

“Underneath. Um—that’s right.” I drank some more mint tea. “It’s all amazing hot. Aside from volcanoes, the only openings to it are those faults. And they move. The faults shift. But these big ones, the earth doesn’t erase them, like it might the little ones. The big ones the earth needs. They’re like the belt in your breeches, to pull in tight when you lose weight, or to let out when you gain it.”

Oswin looked at his stomach. “It’s not that big. My belly.”

I shook my head. “They say girls are vain. Every man I’ve ever met was just as bad. Anyway, the earth line here is one of the big faults under the island. It’s part of a web of faults under the Pebbled Sea. They feed the other volcanoes around here, and the earthquakes. And the smaller faults split off from the big ones, like, I don’t know, fingers from the hand.”

“A network, you say,” murmured Oswin. “Throughout the Pebbled Sea.”

“And the lands around them. The world adjusts itself all the time.” It was getting cool as the sun passed behind the mountain. I got to my knees, wincing.

Then I felt it, far in the distance. “Oswin, grab the horses. We’ve got another shock coming, and it’s going to be bad.”