The Hogwarts Express pulled into Hogsmeade as the sun dropped behind the mountains. Rowan carried his trunk in his right hand. His left still wouldn't grip properly in the cold.

  He told them on the train. Edmund and Poppy hadn't heard the details, only the Prophet article and what Lawrence had written over the summer, and it was Lawrence who finally said "Just tell them" somewhere north of York. So Rowan did. He told it the way you tell something you've already told three times to people with clipboards. When he finished, Poppy was wiping her face with her sleeve and Edmund was looking at the floor like it owed him money. Iris had turned toward the window at some point during the telling and hadn't turned back.

  Lawrence sat through all of it without moving.

  Later, while Iris slept against the glass, Edmund told Rowan that her parents had nearly pulled her from Hogwarts. Her father still wouldn't talk about the attack. Her mother had spent weeks convincing him to let Iris return.

  "I heard from Poppy," Edmund said. "On the platform. Iris told her things she didn't put in letters." He picked at a loose thread on his sleeve. "Her dad wouldn't even come to King's Cross. Her mum brought her."

  The thestrals pulled their carriage up the hill. Edmund talked about his summer, his mother taking him to Cork to see relatives, how he'd accidentally set his cousin's curtains on fire trying to demonstrate the Lumos charm. Rowan let the words wash over him.

  Weasley was waiting in the entrance hall. She got him into an alcove and cast a privacy charm, and the brisk efficiency of it told Rowan she'd been planning this interception since his name appeared on the Express manifest.

  "The Healers' report came by owl. I want to hear it from you."

  He gave her the short version. Two more weeks on the potion. Left hand still unreliable.

  She handed him a folded parchment. "The Headmistress has offered accommodations if you need time."

  "No."

  She looked at him for a moment. Whatever she saw, she let it go. "Feast in ten minutes."

  Rowan and Lawrence unpacked in the third-year dormitory while Hector Fawley tried to convince Lawrence to try out for the Ravenclaw Quidditch team.

  "Tell him he's wrong," Hector said to Rowan. He'd arrived carrying a stack of tryout fliers and an expression of deep personal conviction.

  "He's not wrong. I've seen him on a broom."

  Lawrence threw a sock at his head. Hector looked personally betrayed and spent the next five minutes talking about how Poppy Sweeting was trying out for Beater despite being, in his words, built like a fence post, and how Imelda Reyes had told him she was going to flatten whoever Ravenclaw put up as Seeker.

  Hector continued in this vein while they finished unpacking, covering the tryout schedule, his predictions for each house team, and his ongoing campaign to get Amit Thakkar to attend a match without bringing a book. Lawrence folded his robes and stacked his textbooks and let Hector talk, and Rowan noticed that he was checking his book bag for the third time, the same way he used to check it before exams. His hands were steady. His face was somewhere else.

  Rowan sat beside Iris at the feast. She presssed her shoulder against his for a second and then reached for the water jug.

  "Ricketts predicted the end of the world four times last year," Hector announced from down the table, to nobody in particular. "The seventh years are running a book on which month she picks next."

  "Who's Ricketts?" Iris asked.

  "Divination," Hector said, as though this explained everything.

  After the feast, Rowan lay in bed with the ritual manual under his pillow. Hector was snoring already. Lawrence was still reading, pages turning at regular intervals, and the sound of it was familiar enough that it should have been comforting. The moonstone was the only piece he couldn't get. He went over the preparation sequence again anyway, the way you'd keep checking a locked door even though you know it's locked.

  He stared at the ceiling until Lawrence put his book down and blew out the candle. Neither of them said goodnight. They hadn't since August.

  The first week of classes settled into a pattern. The core curriculum confirmed what Rowan already suspected about the third-year level, and he spent most of those lessons on nonverbal practice or reading the ritual manual behind a textbook cover. The new electives were where the work was.

  But Defence Against the Dark Arts came first, and it came with a Boggart.

  Hecat had them line up and face it one at a time. A Gryffindor girl got a spider and put it on roller skates. A Ravenclaw boy got a banshee and took its voice away. Edmund got an exam paper marked Troll and turned it into a paper dart that sailed into the wall.

  Iris went up.

  The trunk opened and Rowan was lying dead on a stone floor. Blood pooling under him. Eyes open and empty. The Boggart had gotten the details right, the angle of his arms, the colour of his robes. It looked like a body. It looked like him.

  The class went quiet.

  Iris raised her wand. Her hand was steady but her voice wasn't, quite. "Riddikulus." The dead Rowan sat up and sneezed so hard a pair of glasses flew off his face. He didn't wear glasses. The absurdity caught and the class laughed and the Boggart retreated back into the trunk.

  She stepped back into line and didn't look at him. Her hands were shaking. She put them in her pockets.

  When Rowan's turn came he walked up with his Occlumency locked tight. He was curious what the Boggart would find. His worst fear had shifted over the summer, rearranged by violence and everything that came after, and he didn't know what shape it had settled into.

  The Boggart shifted. What stepped out of the trunk was Rowan.

  Older. Maybe twenty. Same face, but the expression was wrong. The eyes were flat and empty and they looked at the real Rowan the way you'd look at something stuck to your shoe. He held a wand in one hand. The other was stained dark. His posture said he'd been standing like this for a long time and nothing had bothered him in years.

  Someone in the back row inhaled.

  Rowan cast Riddikulus without speaking. The older version tripped over an untied shoelace, landed face-first in a puddle that hadn't been there a moment ago, and came up sputtering with a frog on his head. The class laughed. The Boggart collapsed into smoke.

  He walked back to the line. Hecat watched him from the front of the room.

  After class Iris fell into step beside him in the corridor. They walked for a while. She was chewing the inside of her cheek.

  "Don't become that," she said at the junction where their paths split.

  She turned left toward the library. Rowan turned right toward Ancient Runes.

  Fenwick opened his first lesson by drawing two runes on the board, Ansuz and Isa, and asking what would happen if you carved them side by side. Three students offered answers. Fenwick listened to each one and then said "No."

  "Two valid runes," he said. "No magical effect. Why?" He waited. Nobody had an answer. "Because runes are not spells. You cannot line them up like words in a sentence and expect meaning. Different system entirely. By June you'll understand how the system actually works. For now, copy both runes and list every association from chapter one. We'll spend the next three lessons discovering why all of those associations are inadequate."

  He put the chalk down and sat on the edge of his desk and waited while they wrote.

  Rowan had been using runes for two years. Luminaires, ward arrays, a summer of advanced work with Nicholas Flamel. He'd built functional products and sold them and they worked and he'd assumed that meant he understood the underlying principles. Over the following weeks, Fenwick took apart even basic pairings in ways that showed him otherwise. The Isa-Thurisaz interaction he'd been using in his window wards had a calibration problem he'd been compensating for by trial and error all summer. Fenwick identified the resonance pattern in the third lesson and solved it on the board in four lines of chalk.

  Care of Magical Creatures was Ravenclaw-Hufflepuff, which meant Edmund and Poppy were in the section. Howan had set up at a table near the paddock at the edge of the Forest. On the table were three wicker crates, and from inside them came sounds: a low purring from one, a series of sharp clicks from another, and from the third, a noise that sounded like a very small person grumbling about the weather.

  "Right," Howan said. "Who can tell me the difference between a Kneazle and a housecat?"

  Poppy's hand went up so fast she nearly hit the boy standing next to her. "Kneazles have a lion-like tail, spotted or speckled coat, and large ears. They're exceptionally intelligent, rated XXX by the Ministry, and they can detect untrustworthy individuals. Crossbreeding with domestic cats produces half-Kneazles, which is where most of the magical cat population actually comes from, because purebred Kneazles require a licence under the —"

  "Thank you, Miss Sweeting." Howan opened the first crate. A tawny, speckle-coated creature the size of a large cat stepped out onto the table, surveyed the class with an expression of withering appraisal, and sat down. Its tail, lion-tufted at the tip, flicked once. "This is Mab. She doesn't like most of you. Don't take it personally."

  Mab looked at the class. Her gaze stopped on one Ravenclaw boy, lingered, and moved on. The boy went red.

  "Kneazles can tell when someone's lying to them," Howan said. "They can tell when someone's hiding something. They can tell when someone's afraid, and they can smell an Animagus at fifty yards. They're also extremely particular about who handles them and they bite when they're unhappy. Miss Sweeting, feed her."

  Poppy approached with a piece of dried fish from the supply table. Mab sniffed her hand, considered the offering, and accepted it with dignity. Then she butted her head against Poppy's wrist.

  This text was taken from Royal Road. Help the author by reading the original version there.

  "That means she likes you," Howan said. "It won't happen for most of you. Mr. Ashcroft, you're next."

  Rowan held out his hand. Mab sniffed it. The sniffing went on for longer than it had with Poppy, the Kneazle's whiskers brushing his knuckles, her ears flattened forward in concentration. Then she sneezed directly onto his fingers and turned her back on him.

  "That's not bad," Howan said. "That's neutral. She'll come around. Or she won't. Mr. Haggarty."

  Edmund approached with a piece of fish and the enthusiasm of a person who had no idea what was about to happen. Mab looked at him, looked at the fish, stood up, walked across the table, and climbed into his lap.

  "She never does that," Howan said, and looked genuinely surprised.

  Edmund froze with both hands in the air, the fish dangling from his fingers, and a Kneazle purring in his lap. "What do I do?"

  "Feed her the fish and don't move."

  Poppy spent the rest of the lesson moving between the three crates, asking Howan questions that went so far beyond the curriculum he eventually told her to come back after class and they'd talk properly. She came back looking like she might burst.

  "He asked if I'd be interested in helping with the breeding programme," she told Edmund on the way back to the castle. "He said most third-years can't tell a Kneazle from a cat and he needs someone who actually knows what they're doing."

  "That's brilliant," Edmund said.

  Poppy grabbed his arm and squeezed it.

  Rowan spent most of History of Magic reading the ritual manual behind a Potions textbook cover while Binns drifted through the Statute of Secrecy. Half the class was asleep. Iris was taking notes with the focused determination of someone who refused to let a ghost bore her into submission.

  Binns caught him not paying attention.

  "Mr. Ashcroft. The primary goblin objection to the 1692 Statute."

  Rowan closed the manual under the textbook. "They weren't consulted. The Statute was negotiated entirely by wizards and the goblin clans only learned about it after ratification. They argued they'd been bound by terms they hadn't agreed to."

  "Correct. Five points to Ravenclaw." Binns turned back to the blackboard without waiting to see if there was more.

  Iris kicked Rowan's ankle under the desk. He went back to the manual.

  Saturday before dawn, Rowan put his hand on Lawrence's shoulder. Lawrence was dressed in under a minute. They found Iris already waiting in the common room, boots on, knapsack over one shoulder. She'd borrowed a pair of Lawrence's work gloves, which were too big for her and made her look like she was about to clean out a gutter.

  "You've got a week left on the potion," Iris said, looking at Rowan's left hand.

  "It's fine in the cold if I keep it moving."

  "It's October in the Scottish Highlands."

  "I cast a warming charm on the glove. It'll hold for a few hours."

  She looked at Lawrence, who was already at the door. He'd wanted to go the first night back. Rowan had talked him into waiting for the weekend, and that was as much waiting as Lawrence had in him. His mother's hands shook worse every month. The moonstone wasn't going to get closer to forming while they sat in the common room.

  Iris pulled on her gloves. "If your hand locks up, we turn back."

  "Agreed."

  They left through the passage behind the third-floor tapestry and crossed the grounds in the dark. The lake was black. The Forest was a line of darker black at the southern edge. Nobody talked. Lawrence had been like this since August, and Rowan had stopped trying to fill the silences because Lawrence didn't want them filled.

  Iris checked the bearing with a Point-Me and corrected Rowan's map three times in the first twenty minutes. She had a better eye for distances than he did. The first correction was a stream he'd placed fifty yards too far west; the second was a rock formation he'd sketched from memory and gotten wrong; the third was an entire section of trail he'd invented by combining two separate paths into one.

  "Your mapping is terrible," she told him.

  "I know."

  "I'm doing the map from now on."

  The ground rose after the first hour. The trees changed from broadleaf to pine, the soil going rocky underfoot. The mist thickened at the higher elevation and cut their visibility down. Both of them had their wands out.

  A branch snapped off to the left.

  Rowan stopped. Iris was beside him half a step later, wand left while his covered right. Lawrence dropped into a crouch behind them.

  The centaur came around a pine trunk. Young by centaur standards, chestnut coat, longbow unstrung across his shoulders. He looked at the three wands pointed at him and waited.

  "Starweaver sent word," he said. "You sought moonstone."

  "Still am," Rowan said. "Iris Caldwell and Lawrence Goode."

  "Thornmane. Starweaver is my mother's brother." He looked up the slope toward the thinning trees. "You're heading into the highlands."

  "What's between here and the ridge?"

  "Thornbacks along the treeline. Dormant during the day if you don't disturb them." He turned his head slightly, glancing up through the canopy. "Their numbers have been growing. They've pushed close to our grazing lands and we can't drive them back permanently. Starweaver said you accepted a debt when you took what we offered. If you thin their numbers in the high passes, we'd consider it a step toward repayment."

  "How much of the debt?"

  "I can't answer that yet." He looked at Rowan directly. "Be careful past the first ridge. There are old structures in the high valleys. We don't go near them."

  "Why?"

  He was already walking away.

  Iris watched him go. "Did he just tell us to fight the thornbacks and then refuse to say why we shouldn't go past the ridge?"

  "He told us what he wanted us to know," Lawrence said. "The rest was a warning."

  They climbed for another hour. The forest thinned and the terrain opened up, the pines growing sparse and stunted and the ground turning to heather and exposed rock. The wind picked up as soon as they cleared the tree line. Rowan's warming charm guttered and died inside five minutes, the wind shearing it away faster than he could recast, and his left hand went numb shortly after. He switched his wand to his right.

  Iris kept mapping. She'd worked out a system, parchment braced against a flat stone, ink charmed to resist the wind, compass headings noted at each change of slope. She was good at it. She caught features Rowan had missed entirely: a spring that emerged between two boulders, a line of iron-stained rock that might indicate a fault, a series of shallow caves cut into the southern face of the ridge that looked natural but were too evenly spaced.

  "Those aren't natural," Iris said, looking at the caves.

  "No." Rowan studied them. The spacing was regular. Someone had carved them, or enlarged them, a long time ago. "Mark them. We'll come back."

  Lawrence worked the ground ahead of them. He turned over rocks and checked exposed mineral faces, splitting likely stones with a tap of his wand and examining the interior. His hands were raw from the cold. He didn't stop.

  They found their first promising reading on a south-facing slope at the top of the second ridge. Rowan's detection charm picked up elevated magical resonance in the feldspar, and for ten minutes all three of them searched the outcrop, turning every stone, checking every crack and hollow.

  Nothing. The resonance was there but the moonstone wasn't. The conditions were right but the centuries of accumulation hadn't finished the job.

  "Could be a hundred years away from forming," Rowan said.

  Lawrence straightened up and looked at the next ridge. "Higher."

  They climbed. The terrain got worse. The heather gave out and there was nothing but rock and scree and patches of old snow in the shadows of boulders. Rowan's boots slipped on loose stone and he went down hard on one knee, tearing his trousers and scraping his palms. Iris caught his arm before he slid further.

  "All right?"

  "Fine."

  He wasn't fine. His left hand was a block of ice and his knee was bleeding and they were further from the castle than any student was supposed to be and the wind was coming in gusts now that made conversation difficult. But the second promising reading came an hour later, stronger than the first, on a high exposed shelf where the lunar sightlines were unobstructed in three directions.

  They searched for forty minutes. Lawrence was methodical and thorough and his face got tighter with every stone he split open and found empty. Iris mapped the shelf's orientation and calculated the moonlight angles for each phase. The numbers were good. The conditions were as close to ideal as they were going to find. And there was nothing there.

  Lawrence sat down on a rock. He pressed his palms flat on his knees and stared at the ground between his boots.

  Rowan gave him a minute. Iris was still mapping, adding detail to the parchment, working outward from the shelf toward the next ridge. She looked up and caught Rowan's eye and shook her head slightly. Not now.

  "The readings get stronger higher up," she said eventually, rolling the parchment.

  Rowan looked at the sun. Past its peak. They'd been out since before dawn. "We should head back."

  "One more ridge," Lawrence said.

  "We don't have the daylight."

  "We have three hours."

  "Three hours to get back. We barely have that."

  Lawrence looked at him. His jaw was set and his eyes were flat and patient in a way that had nothing to do with calm.

  "Next Saturday," Rowan said.

  Lawrence stood up.

  They started back down. The descent was harder than the climb in places where the scree had shifted. Iris went first, picking the route, and Rowan followed and Lawrence came last. Nobody talked. The wind dropped as they got below the ridgeline and into the shelter of the terrain.

  They were back among the pines, an hour from the castle, when Iris stopped.

  "Rowan."

  He stopped. She was looking at the ground.

  Silk. A strand of it, strung between two tree roots, thick as twine and sticky when Rowan touched it with his wand tip. It stretched and held. Thicker than spider silk, tougher, with a faint iridescent sheen in the failing light.

  Another strand, a yard to the left. Then another. The ground between the pine roots was laced with it, an irregular mesh that radiated out from beneath a slab of mossy rock.

  "That's a thornback web," Iris whispered. "Poppy showed me a diagram in her field guide. The radial pattern, they lay it flat, across the ground."

  Rowan looked up. The canopy was thickening overhead and the light was going and nothing moved in the mist between the trunks. The web was fresh, the strands taut and clean.

  "Thornmane said they den along the treeline," Lawrence said.

  "We're at the treeline."

  A sound. Something clicking. A rapid, dry staccato, like someone running their fingernail across the teeth of a comb, except it came from multiple directions.

  Iris took a step backward. Her boot caught a strand of the web. It held for a moment, stretched, and snapped with a sound like a plucked string.

  The clicking stopped. All of it, at once, in every direction.

  Then something moved in the undergrowth to their right. Low, fast, and far too large for any spider Rowan had seen in two years of living near the Forbidden Forest. A dark shape, bristling with spines along its back and legs, slipping between the tree roots with a horrible fluid efficiency. He saw the sheen of its exoskeleton before the mist swallowed it again.

  Another one. To the left. This one didn't hide. It came around the base of a pine and stopped in the open, ten feet away, and Rowan got his first clear look at a thornback.

  It was the size of a large dog. Eight legs, each one studded with barbed spines from joint to claw. The body was armoured in overlapping plates that looked like dark horn, ridged and scarred. Too many eyes, clustered in a raised dome at the front of its head, reflecting the dim light in wet black points. Mandibles the length of Rowan's fingers worked slowly, testing the air.

  More clicking. Behind them now. And above. Rowan looked up and saw another one clinging to a pine trunk fifteen feet overhead, perfectly still, its belly pale and exposed against the bark.

  "That's an ambusher," Iris breathed. "The ones in the trees shoot webs."

  Rowan counted. Three on the ground that he could see. Two in the trees. The clicking said there were more. The web under their feet meant they were standing in a hunting ground, and the snapped strand meant every thornback in range knew it.

  Lawrence had his wand up. His hand was steady. "Fire," he said. "They're vulnerable to fire."

  "If we start casting, the rest of the den comes," Rowan said.

  The thornback on the ground took a step closer. Its spined legs made no sound on the pine needles. The mandibles opened wider and Rowan could see the venom glistening on the curved tips.

  Iris pressed her back against his. Lawrence shifted to close the triangle. Three wands out, three directions covered. The mist crept between the trees. The clicking started again, louder, from everywhere.