Free Melting Stones by Tamora Pierce

Evvy, it's like you've been sniffing dragonsalt. Enough!"
    Carefully Rosethorn put her hands on the moss. She talked it into letting go of the stone. Piece by piece, she lifted it free and moved it to a shady patch. I called a fistful of lesser stones in the soil to come together, bracing the marker. They helped me to push it until it was straight again. When that was done, Rosethorn and I mounted up and followed the others along the trail.
    Fusspot couldn't keep still for long. We hadn't gone more than five more markers up the slope of Mount Grace when he drew his horse even with Rosethorn's. "I want her left at the village next time! She is a distraction and a nuisance! She is—"
    "What in the Green Man's mercy?" Rosethorn turned her horse down a path among a tumble of rocks. Myrrhtide might think she was riding off in a temper, but I knew better. She hadn't even heard him. Something else had gotten her attention. I looked at Jayat.
    "There's a better place to see it from," Jayat called to her, and turned to me. "How did she know?"
    "How did she know what?" I asked. Fusspot shoved in front of us to ride after Rosethorn. Jayat didn't answer; he just followed Fusspot, and I followed him.
    Rosethorn led us down among rocks that got taller and taller. These were big,
gorgeous
slabs of flat stone. They looked like some giant had cut them from the mountainside with an ax. We came out on a ledge. Stone rose behind us, and the ground sloped far below. The slope ended in a small canyon filled with dead trees.
    Jayat sighed. "This is the worst place. My uncle and I found it two weeks ago as we were hunting."
    I dismounted and put Luvo on the ground. The fizzing in my blood was starting to annoy me. It made me fidget, when I am not by nature a fidgeting person. I rested my hand on one of the slabs behind us, hoping the nice, steady granite would calm me down. Instead its roots warned me of what was rising under our feet.
    "Shock!" I yelled. How did it come up on us so fast? It must have welled up under the mountain. "Earth shock!"
    The others threw themselves off the horses, which were panicking. The animals had felt the coming shakes almost as soon as I had.
That
was embarrassing. I should have known faster. "Luvo, why didn't you warn me?" I cried.
    "It is too quick. Too close," he said.
    I dragged my horse's head down. It fought, until I yanked my jacket off and covered its eyes.
    The earth shuddered and crackled. Trees fell into the dead canyon from its sides. Boulders tumbled along with them. Everything smashed to bits at the bottom. The wave of power struggled to reach the surface, fell short, and sank back.
    We waited and did nothing, only listened. Luvo and I sent our magics into the ground, feeling for more waves. We found nothing. On the mountain and in the canyon, more stones fell. Big ones, little ones… They welcomed the chance to change themselves. I wished them well on their journeys to new shapes.
    "That was very, very close." Jayat, like me, had covered his horse's eyes to keep it calm. He began to unwrap his shirt from his horse's head.
    I stared at the long scars on Jayat's back. He shrugged and said, "Not everybody was sad when the foreign lords killed as many pirates as they could find."
    I nodded. I could see that he wouldn't be too upset at that. "Luvo? Are you all right?" I asked.
    Luvo wandered over to the ledge to look down into the dead canyon. "The crack in the earth beside the road closed, but a new one opened down below. I do not recommend that you try to use the new line of power, Jayatin. There are seams of quartz crystal around and below it. They will make any magical strength drawn by a human somewhat irregular."
    "Are you sure we would do so badly, Master Luvo?" Jayat smiled patiently, as if he spoke to a child. "We've gotten pretty good at finding ways to draw on this stuff, you know. We have to, you see. We're just a little bit desperate at the moment. Perhaps our skills don't look like much to