"It sounds like a relay engaging and then dropping out," he said. "Not necessarily a bad relay. It sounds as if something is telling it to stop." A younger engineer straightened beside the cabinet while the older one narrowed his eyes. Natalie approached without the expression Marcus had expected, not impatient with him but interested in what his words might mean.
"And how would you know the difference?" the older engineer asked. "I used to repair electrical equipment," Marcus answered. "Commercial washers, pumps, control boards, a little climate-control work. I'm not certified on your building system, and I wouldn't touch a live cabinet without the right people here. But I've heard that particular sound before." He could feel the caution spreading through the room, the quiet arithmetic everyone performed when deciding whether a stranger's observation deserved their time.
The older engineer was named Peter Lang, a man who had spent sixteen years managing increasingly complex building-control systems. His doubt was understandable, Marcus thought; Peter was responsible for safety, liability, and equipment worth more than Marcus had earned in several years. What bothered Marcus was not the doubt itself, but the quickness with which Peter's eyes returned to the cleaning uniform as if the fabric had already answered the question. He stayed where he was, hands visible and away from the panel.
"What are you suggesting?" Natalie asked. Marcus pointed toward the fan assembly behind the grating, then toward the exposed control module. "That the unit may be responding correctly to bad information."
It starts, receives a condition it believes is unsafe, and stops. You can replace every relay in that cabinet and still hear the same click if the wrong signal keeps coming back. Peter's expression changed, not to belief yet, but to the attentive caution of a technician hearing a plausible alternative.
"Our controller shows normal status," Peter said. "It may," Marcus answered. "But does it show what the room is actually doing, or what the sensors are telling it the room is doing?" For several seconds no one spoke, and the question hung there beneath the hum of the air conditioning.
Natalie glanced at the wall clock. It was approaching midnight, and a delegation from a major hospital network would be using this room in less than nine hours. The meeting itself was not worth the amount of panic in the hallway; what mattered was that months of negotiations and an enormous investment in Meridian's technology would be judged in part by the reliability of a single live presentation. If the room overheated, the demonstration servers could be moved elsewhere, but not without explaining why the company's own headquarters could not keep a conference suite stable.
She looked directly at Marcus. "Can you help us check that theory?" He nodded, then shook his head just enough to make the distinction clear. "I can help you think through it, and I can tell you what I'd inspect."
But Peter and his team should operate the equipment. It's their system, and they have the authority and test instruments. Peter seemed surprised by that answer, as though he had prepared himself to fend off a man who would insist on proving his expertise by reaching into the cabinet.