They found the transit records they needed in the High Ring transition zone archive, which was housed in a building that looked like a minor administrative office from the outside and contained, inside, the secondary filing system for Records that pertained to High Ring residents and their intersections with the rest of the city. The building had proper locks, which Alden dealt with in the time it took Seren to read the notice posted beside the door about restricted access and the penalties for unauthorized entry.

She did not comment on this.

The woman named Vel was in the transit records. Not under that name — under a reference number attached to a case file that had been opened and then closed within forty-eight hours, the opening notation citing a medical transport request and the closing notation citing resolution without further action required. The medical transport request had been submitted by a High Ring address that Seren did not recognize but which Alden, looking over her shoulder, identified as a courier address — a location used by multiple parties to submit documentation without attaching a permanent address to it.

The case file had a photograph attached.

The woman in the photograph was perhaps forty, Marked, with the close-cropped hair of someone in a professional or institutional position. She was not looking at the camera. Her wrist was visible at the edge of the frame, and the Vaultmark there was partially obscured by shadow but present.

Below the photograph, handwritten in the margin: V. Sole. Transition zone, upper maintenance passage. Cause: exposure.

V. Sole. Vel was a diminutive. Or a truncation.

“She was Marked,” Seren said.

“And she died in the upper maintenance passage of the High Ring transition zone, which is not a location where people die of exposure accidentally,” Alden said. “That passage is temperature-controlled. It’s a service route for Vault maintenance personnel.” He paused. “She would have to have been there deliberately.”

They were back in the Underways before the building’s standard morning shift began. The tunnel air was cold and tasted of stone. Seren walked with the photograph description memorized and the case reference number written in her personal ledger in the abbreviated notation she used for things she did not want to be immediately legible.

They were coming up through the Middle Ring access point, moving toward the exit ladder that would bring them out into the service alley behind The Last Records, when she heard the footsteps.

Not echoing from ahead or behind. Above, and slightly to the left — the specific sound of someone walking in the corridor that ran parallel to the tunnel at street level. The sound was wrong for the hour; this corridor should have been empty until the third bell.

Alden heard it at the same moment she did. He stopped and put a hand up.

They stood still in the dark.

The footsteps passed, slowed, passed again. They did not go away entirely. Someone was in the street-level corridor and not moving on.

Alden moved the lamp shield to kill most of the light, leaving only the faintest glow. In the near-dark, standing close enough that she could hear him breathe, Seren was aware of the cold coming through the stone wall and the warmth coming from the few inches of air between them. She kept her breathing even. Her hands were still.

This was the position she had learned to manage in the early years of her job — waiting in uncomfortable conditions without her discomfort becoming visible. She had become very good at it.

The footsteps above went quiet.

They waited another two minutes before Alden moved again, and she followed him to the exit ladder and up into the service alley.

The alley was empty. The person in the corridor, whoever they were, had gone.

The sky above — the Vault, grey and still — was brightening toward the first morning bell. Seren straightened her coat and checked that her ledger was still in her inside pocket. It was.

She was about to turn toward the Records back entrance when she heard her name.

Not Seren. Vale. The way someone said a name when they were testing whether the person wearing it would respond.

She turned.

Cassian Rook was leaning against the far wall of the service alley with the posture of someone who had been waiting for a while and had made himself comfortable about it. He was wearing a coat she had not seen before, good fabric, the kind that came from High Ring merchant stalls rather than the Lower Rings secondhand markets. His hair was tidier than she remembered. He looked, in the grey morning light, like a version of someone she had known — close enough to be recognizable, different enough to require re-assessment.

His eyes went to her first. They were always going to go to her first. Seren had known this, without naming it, since they were fourteen years old and she had looked up from a task to find him looking at her and looked away before either of them had to decide what the looking meant. That dynamic had not changed. She noted it and moved past it.

Then he saw Alden, and something shifted.

“Alden,” he said. His voice was light. It was always light. “I heard you were back in this part of the city.”

“Cassian,” Alden said.

The silence that followed had the specific quality of a silence between people who have a great deal to say and have decided, by mutual but unspoken agreement, not to say most of it.

“I’ve been back for a while,” Cassian said. “You two look like you’ve been in the maintenance tunnels.” He looked at Seren’s coat, which did have stone dust on the left sleeve. “Records work?”

“Something like that,” Seren said.

“How long?” Alden asked. Meaning: how long have you been back.

“Long enough,” Cassian said. Which answered nothing.

He moved then, pushing off the wall and stepping forward into the slightly better light near the Records building’s back wall. He moved the way he had always moved — with a kind of deliberate ease, the ease of someone performing ease rather than feeling it, which she had learned to distinguish by seventeen and had never since been able to ignore. But there was something else in it now: a different quality of deliberateness, more contained, more careful.

And on his wrist, visible at the cuff of the good coat, there was a mark.

She looked at it without appearing to look at it, which was a skill she had developed. Round form, the enclosed arc of a Vaultmark. But the edges were not quite right. And as the morning light moved across it with the slight variance of the Vault shine, the mark shifted — not dramatically, not visibly to someone not looking for it, but a subtle subsurface movement, like something liquid moving beneath a surface that appeared solid.

Vaultmarks did not do that.

“You’ve been in High Ring,” she said. It was a reasonable inference from the coat and his ease in what was, technically, a Middle Ring adjacent zone.

“Here and there,” Cassian said. His eyes, she noticed, had moved to Alden and stayed there for a moment before coming back to her.

Alden was watching Cassian with the particular quality of stillness that she associated with him paying very close attention to something.

“You should be more careful about where you surface from maintenance tunnels,” Cassian said, mildly. “There are people paying attention to unusual movement patterns in this part of Middle Ring.” He looked at Seren directly. “Paying attention to Records personnel specifically. The intake from three nights ago attracted interest at levels above Orwin Pell.”

Seren looked at him. “How do you know about the intake?”

“I hear things.” He said it without elaboration. He had always been good at that — saying things that contained exactly the right amount of information to make you want more and not enough to give you anything to work with.

“The mark on your wrist,” Alden said. His voice was even. “It’s not a Vaultmark.”

The quality of the silence changed.

Cassian did not look down at his wrist. He looked at Alden with the expression of someone deciding how to respond to a statement that was accurate. Then he smiled — the familiar smile, the one that had disarmed people for as long as Seren could remember — and said: “You two should be careful with what you’re looking into. Not everything in this city that looks like an investigation is safe to investigate.”

He left the way he had arrived: smoothly, with no apparent urgency, through the service alley and onto the street beyond. He did not look back.

Seren stood in the alley and looked at the space where he had been.

In her coat pocket, the personal ledger was solid against her ribs. On the inside back cover, in the smallest handwriting she used for things she did not want to lose, she had written two things: THE SKY LIES, and mark moves.

She took the ledger out and added a third line: C.R. — not a Vaultmark. Warned us off.

Alden was still standing where he had been. He was looking at the street entrance where Cassian had disappeared.

“He knew we were here,” Seren said.

“Yes.”

“He warned us.”

“Yes.” A pause. “That could mean several things.”

She looked at the street entrance too. The morning light was getting stronger. In an hour, the Records building would be fully active and her absence would be noticed.

“I know,” she said. She put the ledger back in her pocket and turned toward the Records back entrance. “I need to be at my desk.”

Alden did not follow her in. He went back the way they had come.