Maya leaned over the plan. The dotted blue line stopped against an empty rectangle that the legend called a utility reserve. No equipment rack, no municipal asset number, no maintenance classification explained what lay beyond it. The electrical reading had been steady for months. Something in that part of the building appeared to be using power and communicating with the network, even though the official diagram described no such equipment.
"Can the line be traced physically without interrupting service?" Maya asked.
Owen checked the plan. "Yes. We can follow the accessible route and document what we find."
Maya closed the procurement folder. "Then we'll stop asking the diagram where the cable goes. Let's follow it."
The basement corridor was cooler than the rest of the station. Thick pipes ran along the ceiling, disappearing into concrete walls darkened by decades of maintenance work. The air carried a faint mineral smell mixed with dust and the steady breath of ventilation equipment. Frank Holloway joined the group from the facilities office, bringing an old ring of keys and a clipboard. He knew most of the basement rooms by what had broken in them over the years. He knew where water collected after heavy rain, which door sometimes stuck in humid weather, and which electrical panel could not be opened without shutting down half the hallway lights.
Owen traced the fiber line from the main server room toward the utility corridor while Lena followed the older building plan on her tablet. The line appeared properly supported for its first stretch. Then it vanished behind a large metal panel fastened with screws whose paint had been disturbed. At first glance the panel resembled ordinary electrical access. Up close, the surrounding wall had fresher tool marks than the nearby fixtures.
"We open this panel for maintenance," Mercer said.
Frank checked the number stamped along its edge. "Not under my work orders. This isn't listed as one of our authorized utility access points."
"It could have been installed as part of the technology project," Rebecca replied.
"Then the project drawings should show it," Maya said. "Do we have a modification order?"
Lena searched the plans. Nothing indicated new construction in that section. Maya directed the photographer to document the exterior of the panel, including the screws, markings, and surrounding conduit. Frank then removed it under observation. Behind it, a narrow service space contained a power conduit and the fiber line, both disappearing through a newly reinforced interior partition. Farther inside sat a secured door with an electronic access reader.
"There isn't supposed to be a room back there," Lena said.
Rebecca studied the door. "There used to be mechanical storage in this basement. Maybe the room was converted."
Frank shook his head. "Not there. That was a solid utility partition on the old plans. I was working for the city before you joined the department. Nobody asked facilities to authorize a new room behind it."
Maya looked toward Mercer. "Do you have documentation identifying this space as part of the approved evidence system?"
"Not with me. Before anybody forces entry, I'd like the city attorney notified."