A flock of small white birds rose from the far bank and wheeled over the canal. Lina tipped her head back to watch them. “They sleep inside the warm vents when the wind is bad.”

Elias watched the birds wheel over the canal. “You know that, but not who maintains the vents.”

Her mouth tightened. “You do it again.”

Elias asked, “Do what?”

“Take the thing and pull all the soft off it.” She touched his sleeve with two fingers, not accusing, almost careful. “Then it is only a use.”

He looked ahead so he would not have to answer at once. A narrow crossing joined one terrace to the next: a strip of dark stone over a place where the channel pinched and sped up. Foam gathered at the far side where a metal grate cut the current into white bars. Beyond it the path opened toward sun decks, shallow pools, and people lying half asleep in the light.

“I’m trying to understand the structure,” he said.

Lina made a small sound that might have been amusement if it had not carried so much weariness. “You speak like the tower doors.”

That almost made him laugh, and because it almost did, grief moved under it with a clean hard edge. Niall would have laughed. Niall would have said something dry about being insulted by architecture and then gone dead serious one second later, because that was how he worked—easy until the work turned dangerous. Elias swallowed and kept his eyes on the water.

Lina heard the silence but did not press into it. After a while she said, “There is a song in the stones here. Listen.”