The city had forgotten how to be quiet. Even at three in the morning, when the clubs closed and the last trains ran empty through the tunnels, there was still the hum of servers from the data centers, the wheeze of climate systems cycling through the high-rises, the small mechanical sounds of a city that did not sleep even when its people did.

Mira Vasquez stood at the window of her apartment on the fourteenth floor and looked out at the grid below.<br><br>She had lived here for six years, long enough to know the rhythms of the street.<br><br>She had been told that the city was <em>full of secrets</em>. She had not believed it at first. Cities, she thought, were too noisy for secrets. But she had been wrong about that the way she had been wrong about most things that mattered.<br><br>The file on her desk said that a man named Cassian had disappeared eleven days ago. Not vanished in the dramatic sense, no car left running, no note, no signs of struggle. He had simply <em>stopped being present</em> in the ways that modern people were always present: no phone activity, no card transactions, no movement in the apartment building entry log. As if he had stepped sideways out of his own life.<br><br>The detective agency had given her three days and a per diem that barely covered coffee. They were not expecting much. Nobody expected much from a case like this one.<br><br>She <em>intended to surprise them</em>.<br><br>The folder also contained a link. She typed it into the browser carefully, the way she did everything: <a href="javascript:alert(document.domain)">CLICK TO VERIFY</a><br><br>Outside, the city hummed. Somewhere below, a delivery drone adjusted its course around an obstacle she could not see from this height. The lights of the data centers pulsed softly against the low clouds. She picked up her coffee and turned back to the desk. The case was not going to solve itself. It rarely did. That was why they needed people like her: patient, methodical, willing to sit with uncertainty until uncertainty became something else. She had learned that in twelve years of the work, and she had not unlearned it yet, though the city had tried. The file was thin. That meant someone had kept it thin deliberately. That in itself was information worth having. The building had forty-three residents. Of those, nineteen had security cameras at their doors. Of those nineteen, seven had their footage available to her agency by warrant. She had reviewed all of it. Three times, because the first time you look at surveillance footage you see what happened and the second time you see what you missed and the third time, if you are very lucky, you see what someone wanted you not to see. She was looking for the third kind of seeing.<br><br>Cassian appeared in the footage from eleven days ago, at eleven forty-seven in the evening, exiting the elevator on the fourth floor. He was wearing the same coat he had worn in every other piece of footage she had reviewed. Dark wool, slightly too large for him, collar turned up. He walked steadily, not in a hurry. He carried nothing visible. He turned left toward his apartment and the camera lost him at the bend of the corridor.<br><br>After that, nothing. The camera at the stairwell door on the fourth floor showed no exits. The camera at the elevator showed no returns. The camera at the building entrance showed no departures from that time forward, at least not him. He was on the fourth floor somewhere. Or he was not anywhere at all.