Saryth's breath puffed out in front of him as he followed Kite up the mountain path, staying well away from the edge. In front of him and to his left the mountains towered into the sky, which was a clear, pale blue still tinged with echoes of the vibrant dawn. To his right, if he looked down, the path zigzagged back down to the plains and the road they'd followed from the village where they'd spent the night. It was a steep slope, and there wasn't much by way of vegetation to break a fall, just the occasional wind-twisted tree. The heat of the plains below was now a distant memory. He rubbed his hands together and tucked them under his arms for warmth.

"It's cold!"

"I know," Kite said from in front. "Sorry."

"It's not exactly your fault. Unless you can control the weather and didn't think to mention it to me."

She chuckled, which was what he'd been aiming for, and stopped walking, leaning back against the rock face for a break. Saryth found a convenient ledge and sat down beside her.

"No, I can't," she said, "but it was my choice to leave before dawn, and I knew it would be cold. I didn't want any witnesses to our using the gateway. You did send the letter, didn't you?"

"Yes." He ignored the nagging twinge of guilt.

"Good. Tiana needs to know there's a new gateway in her territory."

"Is it unusual?"

"Very. That's why we're going through it. That, and I'm sick and tired of traipsing round villages chasing rumours of Aeryn. This's probably more of a clue, anyway." She leaned forward, her attention caught by something below. "What's that?"

"What?"

"Down there." She pointed to a cloud of dust at the foot of the mountain. "Looks like a band of riders... Not happy riders either. And they've come from the same town we did." There was only one road, so that wasn't hard to guess. Uncomfortably aware of what the riders had probably come for, Saryth looked away. Kite caught his movement, and turned to look at him.

"What did you do?" she asked, a teasing undertone in her voice. Does she know? Does she suspect? Once again he felt the guilty urge to tell all, but before he could say anything, she shrugged, straightened up and turned back to the path. "Oh, come on. We'd better get to the top before they do." Saryth cast another glance at the riders, then hurried to follow her.

Two turns of the path later, he couldn't bear it any more.

"There were children," he began. Kite kept going, but he knew she was listening. "When I took the letter to the couriers yesterday evening. There wasn't anybody at the Post point, so I looked around the main square. And I saw children locked in manacles. They said they'd been caught stealing food." He stopped talking to catch his breath in the thin air.

"They were hungry?" Kite asked, without stopping.

"Yes." He scowled at the memory of the angry girl and her sobbing little brother. "And when I asked why, they said their mother died and no-one would feed them." Down below, the riders had reached the foot of the climb, and were urging their horses up the winding mountain path.

"Hang on," Kite said, "I thought orphans had to be taken care of by law."

"They said it was because their mother was the town... the town whore. No-one would take them."

Kite stopped walking at last, and turned to look at him.

"So you freed them." It wasn't a question.

"I wasn't going to leave them there! They were going to cut their hands off!"

"Oh, Saryth." She shook her head. "Didn't I say before about subtlety?"

"I was subtle! I used that disguise spell you taught me. I sent them to Tiana with the letter. I didn't even confront anyone!" He'd wanted to. He'd almost hoped Kite's obfuscation spell would fail, that someone would ask him what he was doing as he opened the manacles and led the children away, but they'd walked straight through the town square without any comments from the few people around. They'd even turned their heads so as not to look at him. It had been downright creepy.

"All right," Kite said with a heavy sigh. "It's an improvement." She leaned closer. "Next time use your head! We could have paid off their accusers." Saryth blinked. That option had never even occurred to him. Kite cast a glance over the side at their pursuers, still on horseback and gaining, and started walking again, at a faster pace. "And we wouldn't have had to run up this wretched mountain!"

Saryth held his peace and followed her. The hoofbeats were audible now. He wondered if any pursuers had gone after the children. Or did they think he and Kite had the children with them? Why were they so intent on catching petty thieves, anyway? I hope they make it to Ath Shera safely. I hope Tiana is nice to them.

The path levelled out to a plateau, not the peak, but a large flat area where the path broadened over a shoulder of the mountain. Kite hurried to the middle, stopped, turned, and grinned at him, breathing a little harder than before.

Anyway, we're here now," she said. "I hope. If not, we're going to have problems." The hoofbeats were getting louder. How did they manage to get horses up that path?

"Where does this lead?"

"Actually, I don't know." She looked thoughtful. "Could be anywhere. So be ready for anything."

"... Right."

"Then, let's go," Kite said. She took hold of her staff and made the now-familiar series of gestures. Saryth took a deep breath as the world twisted under her magic, and the breach opened to let them through.

It could have been anywhere, but it was Castellan. Kite knew even before she opened her eyes, and her heart sank. Castellan had a nasty taint to it which no other world had, and she didn't need to see the blasted ruins to know where she was.

"Just my luck," she groused. "Castellan. I hate this place."

"What happened here?" Saryth shivered and pulled his cloak tighter, although it was warmer than the mountain-top they'd just left.

"A disaster. Much like Uamut, in fact." Kite picked her way across the rubble to what might have been a crossroads, trying to triangulate their position. There were only so many leylines, and she knew Castellan's configuration. All the Seekers learned Castellan's leylines.

"But that's completely different!" Saryth protested, following her. She ducked behind a wall and motioned for him to do the same, although there was no sign of anybody nearby. Better safe than sorry.

"It's the same principle," she said. "We need to be quiet. We don't want to get caught." Saryth crouched beside her obediently, and she closed her eyes and concentrated, fumbling for the leylines which stretched out from the gateway they'd just used. I need to teach him how to do this. She rotated the map in her head, trying to make the leylines fit, and groaned.

"What's wrong?" Saryth asked, voice hushed.

"We're quite far from a known gateway. We need to get moving, as quickly and quietly as possible." She stood up. "Come on."

Crossing Castellan, her teachers had said, was an exercise in not being spotted by the natives or any of the dangerous wildlife that inhabited the wastelands around the ruined cities. They had recommended sticking to the wastelands if possible, since dangerous animals were easier to deal with than the humans who still haunted the ruins. The route from their current position to the nearest gateway led through both. Brilliant! Underneath that was a persistent, nagging worry. How would a world like Castellan respond to a sun? I suppose we're going to find out.

After a mile or so of picking their way through the rubble, Saryth returned to his previous question, speaking quietly.

"So how is this like Uamut?"

Kite held up her hand as they came to an open space, and looked about. There was no sign of movement, but she ducked into the shelter of a tumbledown wall nonetheless, and took a moment to answer his question while she watched.

"Essentially," she said, "a similar thing happened. Worlds with sapient dwellers go through phases. Either magic is ascendant, and that's phase one, or they pursue the study of natural laws, and that's phase two. The problem is, transitions are not easy. It is unfortunately quite normal for a phase two world to suffer from something like this."

"But not phase one? Why not?"

Kite made up her mind.

"Right, let's go." She stood up and hurried across the open space, Saryth close on her heels. On the other side she squatted behind another wall and watched again. Still nothing. Maybe it really is deserted. The houses on this side of the open area, which might once have been a plaza or a large road, were smaller and more spaced out. Easier for her to spot any threats. Easier for those threats to spot her.

"Not much further, I think," she said. I hope. "And we don't know, sorry. Some people think it's because of the nature of magic." Saryth gave her an odd look. "Magic requires long and disciplined learning. By the time a student has grown powerful and skilled enough to do something like this," she waved her hand to indicate the general state of the ruins, "they no longer desire it. Although of course, a trained mage who does still want such things is very, very nasty indeed."

A mile or so later the spaced out houses came to an end at a wall which, though somewhat damaged, still stood higher than her head and stretched out to either side with no openings, intentional or accidental. A city wall? She stood on a convenient heap of broken bricks and jumped for the top, pulling herself up cautiously. On the other side was a steep slope littered with rubble but no other sign of habitation. Yes!

"And the other way's not like that?" Saryth asked, making his own jump and scrabbling for the top.

"No, because there is no specific limit to who can use technology. It may take years to master the learning and techniques to make a weapon, but any idiot can pull a trigger." She wriggled round to lower herself to the treacherous footing on the other side, clinging to the wall to steady herself. Saryth, finally seated atop the wall, looked down at her.

"So how do phase one worlds change?"

"Be careful here," she said, as he turned to follow her down. "In phase one worlds - like yours - magic just seems to decline naturally, after centuries of use." He made it unscathed, and she started picking her way down the slope, watching where she put her feet on the unsteady pile of rocks and rubble. "Sometimes that happens with phase two worlds, and sometimes wizards go bad and disasters happen in phase one worlds. But normally we've observed things the other way round. And we don't really know why. All that is just a guess." A guess and a popular topic of discussion among students, at least among those who'd never been to places like Castellan. At the bottom of the slope, Kite turned to look back at the ruined city brooding behind its walls, and shuddered. In front of her the wastelands stretched away, loose earth and low hills, covered with scrubby grass and small misshapen plants.

"We're out of the worst area," she told Saryth. "Hopefully we can make good time now." It would be a long walk to Castellan itself, the city for which the world was named. And there are definitely people there. But we can worry about that later.

"Do worlds keep changing forever?" Saryth asked, as they started walking again.

"Well, we haven't seen it happen, but we've seen dead worlds. So..." she let the words trail off. That had been another topic of conversation during training. Now, having seen Castellan and a few other places, it was much less theoretical than it had been. Saryth didn't speak again, and they walked side by side in gloomy silence. Overhead the sky turned puce with the promise of rain. What a horrible place this is. I wish we were still in Ath Shera. Although that had had its own issues. What had Saryth been thinking? But she knew the answer to that. And really, he had done well to find a single solution to both problems. It wasn't fair to expect him to be familiar with Arvadi ways of handling such issues.

"Saryth," she said tentatively, "I'm sorry I snapped at you about those children." No response. She looked at her companion, realised he'd stopped walking. "Saryth? What is it?"

"There's someone being beaten up over there," he said, nodding to a low ridge a few hundred yards to their right. Kite gaped. She hadn't heard anything. Saryth started walking towards it. Oh no.

"Hang on, didn't I tell you -"

"I'm not going to stand by and do nothing!"

"I didn't say that!" Kite snapped. Saryth spun round to face her, a mutinous expression on his face, but she carried on before he could say anything. "If you want to rescue people, think first! This world is dangerous! Always look before you jump in!"

Saryth blinked in surprise, then turned back to the ridge, but at least he walked with her instead of rushing ahead. As they approached, Kite could hear the sounds of a fight, or, as Saryth had more accurately named it, a beating.

"You think it's over this bit?" she asked him as they reached the ridge itself.

"Yes."

"Right. Take your cloak off. If we need to fight, we can do without them getting in the way. Put them under that rock."

With cloaks and bags hidden, they crawled to the top of the ridge and peered over. Kite's palm was sweaty against her staff. Flinging herself into confrontation with Castellan folk went against everything she'd been taught. But the scene in front of her was not as bad as she'd feared. The ridge encircled a small crater, and on the floor of the crater four scruffy men were laying into someone. The person they were attacking was lying curled up in a protective position, not resisting, and she felt a deep anger rising. Four people wasn't too bad. We can work something out - and then beside her, Saryth stood up, his face set with fury, and plunged into the crater.

"Saryth, wait!" Too late! He flew down the inside of the crater and Kite gave up and followed him down. She heard him shout as he neared the men.

"Stop that!"

"Ey! Inish kevry?" One of the fighters sounded younger, uncertain.

"Tchak!" Another swore, face twisted with anger. Saryth fended off his punch as Kite came up beside him and landed her own punch on the uncertain one, following up with a kick. He staggered backwards and sat down, folded around his stomach, gasping. Saryth tackled the older man with a knee to the middle and an elbow to the head, then turned to grab the staff that a third man was bringing down in a strike. Kite dodged the fourth man's attack, then swung her staff low to trip him, and by the time she'd finished making sure he wasn't about to get up, the only one standing was the younger one she'd kicked first. He'd staggered to his feet and was edging away, still holding one arm to his stomach, eyes wide. Kite and Saryth turned as one, and he fled.

"Will he bring others?" Saryth asked, shaking his hand as though he'd hurt it. He looked otherwise unscathed, and Kite felt a brief glow of pride. He learns fast.

"Probably," she said in reply. "They're not badly hurt." She went over to where the victim lay. "Now, what do we have here?" She knelt down by the figure, who was thin, long-limbed and dark-skinned, dressed in just a tatty pair of loose trousers, still curled up with arms protecting the head. She eased the arms down gently and brushed long hair back from a dirty face, and stopped at the gleam of the hair under her fingers. Wavy golden hair, shining in the sullen light from the Castellan sun like it had brought its own fire. Hair which did not belong in this world at all. "Oh my."

"Sorry?" Saryth came and knelt down on the other side. "Is she all right?"

"Apart from being beaten up?" Kite grinned with a heady mix of relief and jubilation. "He has a fever. But what I meant was, I think we've found our errant avatar." And we nearly missed him.

"He? I thought it was a girl..." Kite giggled and he scowled. "What?"

"Nothing." Pots and kettles. "Come on. We don't have much time." She gave the figure - Aeryn - a quick check, but nothing seemed to be badly damaged, so she turned him onto his back and stretched his arms out.

"What are we going to do?" Saryth asked.

"We need to make a gateway. That is, you need to make one."

"Me?"

"Yes, you. I don't have the power for this." The admission almost didn't sting. "I'll draw the structure, you get our stuff. Quickly, before they come back."

Saryth ran for the ridge. By the time he returned, laden with cloaks and bags, she had drawn the circle, and was just finishing putting in the glyphs which would direct his magic. She stood up, brushing off her hands.

"Pass me my cloak, and put yours on too."

"Kite?" Saryth asked, pulling his cloak around him.

"Mm?" She fastened her bag strap.

"Why couldn't I understand those people?"

"I don't know why, but the language charm doesn't work on them. Another reason to avoid this place."

"Are they going to be all right?" He looked at the bodies scattered around, still unconscious.

"Yes. None of them are badly hurt." She gave the glyphs a second check. Yes, they all looked fine. Saryth was waiting for instructions. "Pass Aeryn to me, and come in yourself." He knelt down and hoisted Aeryn up with a grunt, easing him over the etched gateway circle. Kite got one shoulder under the limp figure and Saryth stepped in beside her to support Aeryn from the other side, so that he slumped between them. Saryth looked down at the circle.

"So this is an artificial gateway?"

"Yes, but not a permanent one. They need a bit more care, and a lot more maintenance. I'll show you one some day." If I don't get struck off for it.

"So you know where we're going?"

"Setharye. It's near here along the leylines, and it's a lovely place. Aeryn needs a bit of looking after. He's not in very good shape. Are you ready?"

"What do I do?"

"Focus on that glyph there," and she nodded to the glyph directly in front of them. "That's the entry glyph. Hold my hand, so I can help direct you. Just like when you were learning to light candles. The diagram should channel your magic as necessary." Saryth frowned, concentrating, and then just like that the magic poured in. The glyphs caught and channelled it and the gateway opened, as smoothly as a hot knife through butter. Kite fought down a surge of tired envy and stepped in as the world unwove around her.

"I'm so tired!" Saryth felt his knees buckle beneath him, and just about managed to ease Aeryn to the ground instead of dropping him. On his hands and knees, head swimming, he took deep breaths and tried not to pass out. Behind him the twisting glitch of a rent world faded from his perception. The dirt beneath his hands was cool and damp, the air was clean, and the subtle menace of Castellan's atmosphere was gone.

"That's what making gateways does to you," said Kite, who had knelt down with him so as not to drop Aeryn. "Still, we're here, and there's a town just over there. Let's try not to get chased out of this world, all right?"