She half raised her head, blinking at him from between tangled threads of hair, still blind from the light. Blood and grime ran in streaks down her arms and face. Someone had hacked off most of her hair. The Aedolian uniform she had been wearing since the Bone Mountains was nearly shredded. She ran her fingers over the wet stone, caressing it as though it were the cheek of a sleeping child. Her fingernails, Kaden realized, were ragged, bloody.

“Leaving?” she asked quietly.

“Fleeing. We have to move fast, before the next guard comes. Before Matol sends someone else.”

She shivered at the name, then pushed herself unsteadily to her feet. “What do we do?”

“Go with Kiel.”

“Who’s Kiel?”

“Someone who can get us out.”

The still, black pool seemed to drink the lamplight, as though it were pitch or oil rather than salt water, as though anything dipped into it would slide instantly into utter darkness. It was barely more than a pace across, the diameter of a small well, but Kaden could imagine it plunging down endlessly to the very center of the earth.

“This is it,” Kiel said.

Kaden glanced over at Triste. She was trembling, staring at the pool as though into the maw of some great stone beast.

“There’s no other way?” she asked, her voice tiny, terrified. “What about the ship that Kaden mentioned? The one Tan suggested?”

Kaden hesitated. Staring into the dark water, it was tempting to double back, to break out through the main door of the prison, to hope they could hide Triste during the long walk to the underground harbor. It was tempting, and foolish. Triste’s tattered Aedolian uniform did nothing to conceal her identity, less than nothing. Even in shadows, even at a glance, it was obvious that she was a woman, and there were no other women in the Dark Heart. They could sneak into the corridors above hoping for the best, but Kaden was through hoping.

“Too much risk if we go the other way. This will take us straight to the kenta chamber.”

“But the men,” Triste said. “The ones with the bows . . .”

“Will never see us,” Kiel said. “They’re outside the pool, waiting on the ledge above it. We’ll never break the surface.”

“And they don’t guard this?” Kaden asked, gesturing to the pool.

Kiel raised an eyebrow. “Would you?”

“What’s down there?” Triste asked.

“Tunnels. Rooms. Old halls. When the Ishien flooded the kenta, they flooded dozens of the lower passages, too. It was a reasonable decision. No one’s likely to navigate that maze after stepping through the gate, not underwater, not before their air runs out.”

Kaden stared bleakly at the still surface of the pool. “No one except us,” he said.

“Well.” Kiel spread his hands. “We’re going to try.”

“How far?” Triste asked.