House of Flame and Shadow (Crescent City #3) by Sarah J. Maas

“How did Helena transfer the power out of the sword? She didn’t have the Harp,” Bryce said.

“No,” Aidas agreed. “But Helena knew that Midgard possessed its own magic. A raw, weaker sort of magic than that in her home world, but one that could be potent in high concentrations. She learned that it flowed across the world in great highways, natural conduits for magic.”

“Ley lines,” Bryce breathed.

Aidas nodded. “These lines are capable of moving magic, but also carrying communications across great distances.” Like those between the Gates of Crescent City, the way she’d spoken to Danika the day she’d made the Drop. “There are ley lines across the whole of the universe. And the planets—like Midgard, like Hel, like the home world of the Fae—atop those lines are joined by time and space and the Void itself. It thins the veils separating us. The Asteri have long chosen worlds that are on the ley lines for that exact purpose. It made it easier to move between them, to colonize those planets. There are certain places on each of these worlds where the most ley lines overlap, and thus the barrier between worlds is at its weakest.”

Everything slotted together. “Thin places,” Bryce said with sudden certainty.

“Precisely,” Apollion answered for Aidas with an approving nod. “The Northern Rift, the Southern Rift—both lie atop a tremendous knot of ley lines. And while those under Avallen are not as strong, the island is unique as a thin place thanks to the presence of black salt—which ties it to Hel.”

“And the mists?” Hunt asked. “What’s the deal with them?”

“The mists are a result of the ley lines’ power,” Aidas said. “They’re an indication of a thin place. Hoping to find a ley line strong enough to help her transfer and hide Theia’s power, Helena sent a fleet of Fae with earth magic to scour every misty place they could find on Midgard. When they told her of a place wreathed in mists so thick they could not pierce them, Helena went to investigate. The mists parted for her—as if they had been waiting. She found the small network of caves on Avallen … and the black salt beneath the surface.”

Aidas smiled darkly. “She returned to the Eternal City and convinced Pelias that only such a place would be a worthy burial location for him. He was vain and arrogant enough to believe her. So they established the Fae kingdom on Avallen, and she carved his royal tomb into the rock. She spun lies about wanting future generations to worship him, to have to be born with the right blood to have the privilege of attaining his sword, which would be buried with him.”

Aidas gestured toward the Starsword, sheathed down Bryce’s back. “Helena knew Pelias would never part with his trophy, not until he died. And when he did, she at last drew upon the raw power of Avallen’s ley lines to take the star her mother had imbued in the Starsword and hide it.”

“So why the prophecy about the sword and knife?” Hunt asked. “If Theia was so scared of them being reunited, why all this crap about trying to get them back together?”

Aidas crossed his legs. “Helena planted that prophecy, seeded it in Fae lore. She knew that despite her mother’s fears, the sword and knife are needed to destroy the Asteri. She knew that if a scion came along who could claim all three pieces of magic, they’d need the sword and knife to make that power count. Theia’s power, when whole, is the only thing that can unite and activate the true power of those blades and stop the Asteri’s tyranny.”

Bryce’s mouth dried out. A real path to ending the Asteri, at last.

“So where is it?” Bryce asked. “Where’s the last part of Theia’s power?”

“I don’t know,” Aidas said sadly. “Helena told no one, not even me.”

Bryce let out a long, frustrated breath, but Hunt kept pushing the princes. “So to unite the sword and knife, Bryce needs to find the starlight Helena took from the Starsword—the last third of Theia’s power—which is stashed somewhere on Avallen?”

“Yes,” Aidas said simply.

“But how do I make them open that portal to nowhere—and what the Hel does that mean, anyway?” Bryce griped.

Thanatos said roughly, “We’ve been wondering that for eons.”

Aidas dragged a hand through his golden hair. “Ultimate destruction was the best any of us could guess.”

“Fantastic,” Bryce grumbled.

Yet Hunt asked, “If Avallen is one of the stronger thin places, why did the Asteri even allow the Fae to live here?”

“The black salt, in such high quantity, keeps them away. They never realized that its presence drew us as much as it repelled them,” Apollion said with satisfaction. “It has the same properties that made us immune to the thrall of their black crowns.”

Bryce tensed at that, glancing at Hunt, but her mate asked, setting aside his own questions for now, “Did Helena know the Asteri were repelled from this place?”

Aidas nodded. “Once she figured it out, it confirmed her decision to hide Theia’s power here.”

Bryce angled her head. “But why did the mists open for Helena to get through in the first place?”

“The black salt only repels the Asteri; the mists repel everyone else. But certain people, with certain gifts, can access the power of thin places—on any world. World-walkers.” Aidas gestured gracefully to Bryce. “You are one of them. So were Helena and Theia. Their natural abilities lent themselves to moving through the mists.”