Evvy stopped in front of a shallow niche formed by one chunk of stone overlapping another. She rested her forehead against the stone, her back to Briar. “I know he’s a stranger, but he’s a good stranger,” she murmured to the stone. “He’d never hurt me. He’s my teacher. He’s safe.”

Briar shook his head — his foster-sisters would laugh themselves sick to hear him called a teacher. He still felt not like someone who deserved the title, but an imposter. Once we get her a proper teacher, she’ll know I’m not one at all, he told himself. If that idea pinched him a little, it was overtaken by shock. What he’d thought was a shallow niche was really a passage. How had he seen a wall there?

I’m starting to think the rock hides my squat, she’d said yesterday.

She was right.

Briar followed her into the narrow passage. It was just wide enough to admit them and the baskets they carried on their backs, though Briar had to crouch to keep from banging his head. Ten yards down they began to climb steps so old they were worn like bowls in the middle.

“I think there was a cave-in, long ago,” Evvy remarked quietly. “It sealed off my place in front. This was the back way, originally.” She passed through an opening at the top of the stair to be greeted with a chorus of yowls. Briar sneezed: the aroma of cat urine blended with the funk of the passage. He didn’t even try to blow his nose. The worst thing he could imagine just now was a nose clear enough to smell everything afresh.

Evvy’s home was a two-room chamber carved in orange stone. The light was better than it had been in any of the tunnels. It shone steadily from five opaque or cloudy white crystals that were sunk into the stone of the walls.

At first it seemed as if the floor crawled with cats. They meowed and twitched their tails as they mobbed the girl, who knelt to pet each one. A second look sorted them out. There were indeed seven, all as thin as Evvy. They came in a mixed bag of colors: blue-gray with apricot patches, brown-black with orange patches, two brown masks and feet with gold fur, two cinnamon masks and feet with gold fur, black-and-white. Evvy crooned and handed out the contents of a cloth bag she’d pulled from the front of her tunic: chunks of beef and what looked very much like half of the breakfast ham.

Briar inspected their surroundings while Evvy tended her friends. A pile of rags in the corner seemed to be her bed. Directly under a hole in the ceiling was a rough fire pit, with a bucket and a battered pot beside it. A collection of cracked and chipped pottery was stacked by the wall. In a niche he saw a much-battered god figure: a smiling fat man with shriveled flowers at his feet. A thick coat of cat hair covered everything. A ripe drift of scent from the other room told him it served Evvy and her cats as a privy.

The most remarkable thing about the place was the walls. In some areas the rock had been planed smooth, though enough chunks had fallen out that the effect was irregular. That he expected. What he hadn’t expected was the stones embedded everywhere, small ones the size of a dav, others the size of his palm, even some polished rounds and eggs that were probably stolen. Their color and texture varied. One thing was the same for all: They had been pressed into the wall as if it were soft butter, not stone. Briar tried to pry one out, and couldn’t.

“You put these in?” he asked Evvy as the chorus of yowls quieted and the cats ate.

She nodded. “Ria, let Mystery have that. You have your own,” she chided the black-and-white cat. “I thought maybe it’s just dirt, the walls, and that’s why I could push them in.”

Briar rapped the wall around one stone and grimaced. “It’s rock, Evvy. You made the rock act squishy.”

She shrugged. “I didn’t think it was anything special when I did it.” She ducked her head suddenly. When she spoke, her voice was wry. “Though I stopped after I kept getting headaches. I think the Heights were telling me, enough, please.”

Briar surveyed the room again, hands in his pockets. “Can we take some of these back with us?” he asked. “Including your light-stones. We’ll look them up in the books, find out what they are and what-all you can do with them.”

Evvy scratched her head. “Right.” She scrabbled in the rags of her bed, drawing out a large section of cloth. Once she had laid it flat, she began to pry various stones from the walls. They came easily for her. When Briar tried it, they remained stuck fast.

“What I don’t see is how we’re taking the cats,” Evvy commented as she placed stones on her cloth. “There’s ways out of here they can use once we start try loading them, you know.”

“Don’t you get rats through those ways?” Briar asked. He placed Evvy’s basket and the two that he had fetched on the floor and opened the lids.

“No rats,” Evvy said firmly. “The cats gang up on them. They let the rats get in and then jump ‘em.” She bent to scratch the nearest cat’s chin. “They’re good friends to me.” Her lower lip trembled. “I don’t want to leave them.”

“Girls. Always fussing,” Briar said. “Leave it to me.”

The cats finished devouring their food and started a post-feeding wash. Briar slid an oilcloth packet from his shirt pocket and opened it to reveal three catnip leaves. He placed one leaf in each open basket, then woke the power in them. To feline noses it was as if a huge bed of fresh catnip had sprouted in the baskets. They scrambled to get at it.

The moment two cats were in each of the small baskets and three in the largest, Briar closed the lids and fastened them. He lashed one to the rack Evvy would carry, then put the remaining two on his. Once they were set, he changed the power of the leaves to make the cats sleepy. The baskets rocked as the occupants curled up for naps.