The caverns led deeper than any of them had realised, with the nursery and underground village occupying the chambers closest to the surface. As he followed Tarn along rocky paths, through narrow tunnels and across bridges constructed over fast-flowing subterranean rivers, Fenris realised that Aviar must have been preparing for this moment since Aera first arrived and lifted the city into the sky.
Enclosed, source-powered lights embedded into the walls flickered to life as Tarn approached, leaving a trail of illumination to show them the way back to where the others waited in the main chambers with the Avii survivors. Tarn had wanted some time away from all the voices competing for his attention, yet had requested Fenris' company, and so they had both ventured further into the caves, which had been revealed as a warren of twisting paths not represented on any of the Avii maps. Some of the more attuned teachers had wished to accompany them but Tarn had firmly and politely refused their requests.
"When you took me out of the jail cell," Tarn said as they walked, "what were you hoping to achieve?"
It was the question that had pulled at Fenris' attention for months. He'd taken Tarn and Kirya away from Treydolain, driven them into the wilds for reasons that even he had not fully understood at the time, or since. He'd put them in terrible danger, all in the hope that legends and stories he'd been told as a child would reveal themselves to be true: that there would be some salvation beyond the mountains.
That it had all turned out to be true - after a fashion - did nothing to assuage his guilt at acting so rashly. But for all that regret, What, in truth, could he have done differently? If he had not removed Tarn from the jail the boy would instead have been condemned back to the machine rooms, surely prevented from ever escaping again, never able to fulfil the role that had been prepared for him in Aviar.
Kirya, though, was another matter.
"Fenris?"
They had walked in silence after Tarn's question, Fenris alone in his head with his thoughts. "I'd hoped to make a difference," he said, at last. "I'd hoped to change history. I thought I had a destiny. I thought you had a destiny."
"You were right," Tarn said.
Bodies fell through the air in Fenris' memory; those who did not escape Aviar's unexpected descent. Buildings crumbled as the city collapsed and the splintered down into itself. Their arrival had wrought such devastation: if he had not brought Kirya on the journey, then Aera would still be alive - or, at the very least, would have completed the transferral to Tarn in a more controlled fashion, without the city's destruction and the consequent loss of life.
Which would have left them with the body of Tarn inhabited by a god; the boy would have been gone forever, if what Tarn had told them was accurate.
"Being correct does not make one right," Fenris said softly. "I behaved rashly, arrogantly. Yet, even with the knowledge I have now, if I had to choose between the people of Aviar or you standing before me, still yourself, I don't know what I would choose. And that troubles me greatly."
Tarn reached out and activated a series of lights further into the tunnel. "You should choose the city. There are more people. I'm just me. You have to save the most people."
"That is rational thinking," Fenris said, "and is the course of action I would have chosen previously. My responsibility was to keep the valley safe; to protect its people. Now, I feel conflicted. My thoughts are deeply compromised."
"It's a difficult decision because I'm your friend?"
Fenris smiled, an ache in his chest. "Perhaps that is it, Tarn."
"That's why you would still do anything for Kirya," the boy continued, "even after what she did."
"That wasn't her," Fenris said defensively. "She wasn't in control. You know that - you freed her."
"Yes, but you didn't know that when you took her from the spire, or when you kept her safe from everyone else before I woke up."
They walked on in silence, until the path forked in two directions. A gentle movement on the air blew down from one of the tunnels.
"Another way out?" Fenris suggested.
"Perhaps. I think we're close."
"Close to what?"
Tarn looked over his shoulder. "I don't know yet. I'm feeling instinctive suggestions, as if I'm remembering something, but I can't recall all of the specifics."
"Aera's memories."
"They're leaking into me, but they're blurred and broken up."
"Your vocabulary and speech patterns have changed again," Fenris said. "Have you noticed? It is similar to when you used to go to sleep and would wake up with a new word; except this time the leap has been unprecedented."
"It's like the memories," Tarn said as they trudged along, the ground rough and apparently untrodden for a long time. "I know things, but don't know how I know them. With context I can figure out what to do with them, but until then it's hard to understand."
"Context is everything," said Fenris, smiling.
"'Context' is a new one, I think?" Tarn paused and ran his hand along the damp, undulating wall. "Before, I absorbed information accidentally, I think. Aera had established a link with me much like Kraisa had with Kirya, but it wasn't as strong. Aera used my eyes and ears, to see what was happening in the machine rooms, but some of her leaked back along the thread to me."
Fenris sighed. "The rules are changing faster than I can comprehend."
"when I was in Kraisa's mind I saw something. I think she did, too. It was my proximity to the mines which enabled Aera to establish a connection from such a distance."
"Exposure to source appears to act as a conduit," Fenris said.
Tarn tilted his head to one side, as if considering the word for the first time, reminding Fenris of the many guests of the court who would roll a glass of wine to release its aroma before drinking. "Yes, that sounds right."
"I wonder why Kraisa has not taken advantage of this previously," Fenris said. The thought sent a shudder down the back of his neck.
"Aera did something to her, back in the war. Hurt her, somehow. I think it stops her from being able to do everything she wants. Kirya was her daughter; perhaps that made it easier to form a connection, but she's unable to do it otherwise?"
"If only we could do something with this information," Fenris said, "rather than being trapped underground on the wrong side of the mountains."
Continuing, they turned a corner and came abruptly to a halt at a solid wall of rock. A lamp set into the tunnel wall several feet back illuminated the wall only dimly: it was of a different texture and colour to the rest of the tunnel, less clay-like and wet and more like a tight stack of distinct rocks, as if the ceiling had been brought down deliberately.
"We appear to have taken the wrong path," Fenris said, pressing at the wall with his fingers. It was firm and solid to the touch. A layer of brownish dust came away on his fingers.
"Perhaps," Tarn said. He raised an arm, pointing it back down the tunnel, and clenched his fist. The lights flickered and extinguished, dropping them into complete darkness. Fenris blinked at the sudden nothingness, his eyes trying and failing to adjust. He could hear Tarn moving next to him, against the wall.
"What are you looking for?"
"Let me try something."
All was quiet except for the shuffling of Tarn's feet. Fenris stayed still, not trusting his footing in the dark.
"What are you doing?" he asked.
"Concentrating."
"My apologies," Fenris said. The darkness began to press in upon him from all sides, as all sense of direction drifted away.
"You know, Fenris, it is not a weakness to have friends."
Taken aback, Fenris was unsure of what to say, so chose to say nothing at all.
"I never had friends until I left the machine rooms," Tarn continued. "The first friends I met were killed. I think, now, that perhaps they weren't the best kind of friends to have, though they didn't deserve to die. Then I met you. And Kirya. And Tranton. You are all my friends. Also Galisai, and Hatch and Stefan. Although Stefan is very grumpy."
"I have never been imprisoned as you were," Fenris said slowly, considering his words, "but I have rarely had time for friendship."
"That seems silly of you."
That sounded more like Tarn, and the boy's characteristic lack of social niceties brought an amused grin to Fenris' face in the dark. "I suppose it was, Tarn, yes. Friendships do not make difficult decisions any easier. They can cloud one's judgement, or be exploited by others."
"That doesn't matter," Tarn said. "Don't be afraid of it. I try to think of everyone as my friend. Even people I haven't met yet. Maybe even Kraisa, if I can meet her properly. That way it becomes easy again to make decisions, because you don't have to choose between one friend or hundreds of strangers."
"I'm not convinced that that makes entire sense," Fenris said, "but perhaps I will give it a try."
"Good. There," Tarn said, "can you see it?"
At first there was nothing beyond the total blackness, then Fenris' eyes detected a faint, cool glow emanating from the wall, split into a web of angular lines. It took him a moment to understand what he was seeing, then his brain gradually resolved the pattern and he realised that it was light from beyond the wall, shining through hair-thin cracks in the rock. "What is it?"
"I could feel more source-fed lights beyond the wall. I just turned them on."
"We should go back and get the others," Fenris said, having had enough of the encroaching tunnels. "They can help us to dig through."
"Let me try something first. Step back, please, Fenris."
Carefully doing as he was told, acutely aware of the uneven ground beneath his feet, Fenris squinted into the dark. He heard Tarn moving, then there was a thunderous crack and air rushed past him as the wall crumbled and was blown away from them into the tunnel beyond. Light flooded out and Fenris was forced to shield his eyes as they again had to adjust.
"How did you do that?"
"It was part of my training," Tarn said, breathing heavily "but I never managed to do much with it until now. I'm a lot stronger." He shook his hands and arms, as if trying to work feeling back into them after leaning awkwardly for too long. "It takes a lot out of me, though. The power has a limit; once it's used, I have to wait for it to replenish."
"It is truly remarkable, Tarn. How do you know what to do?"
"It's like I said before; I have more knowledge now, I just need to fit the pieces together. The power is building up inside of me again - some of it is growing by itself; the rest is being pulled directly from the ground around us."
"Can all of Aera's students do this?"
Tarn shook his head. "I don't think so. I think they relied more on her, in the same way she kept the city up and the discs flying. Lower levels definitely don't have these abilities; perhaps daemons and totems could do more?"
"We still have much to learn, even now."
Gesturing into the tunnel, Tarn led them on. The passageway opened out into a wider entrance, where crumbled and water-ruined remains of old tables and chairs carved directly into the rock could be identified. More lights flickered on, gradually revealing a chamber as big as the main habitation areas near the entrance. Instead of dwellings the space was occupied by large, complex contraptions: vehicles, ships, other designs that might have been weapons. The entire chamber was a store room, or perhaps a hangar, filled with advanced creations of crafted wood and metal. They bore many of the quirks of Avii craftsmanship yet were evidently of a different era. Unlike the cavern itself, the structures seemed to be in remarkably good condition.
As Fenris watched, the ships started to come to life, illuminating and activating mechanisms. Tarn's presence had awoken them from a long slumber.
"This could be useful," Tarn said, remarkably understating their discovery.
"It's not my place to say," Fenris said, putting his hand around Tarn's shoulders and beaming proudly.