On February 14th, 2200, seventeen workers on the third-shift fabrication line at Zheng-Dao Foundry Block 9 simultaneously entered a behavioral loop. Each worker began repeating the last physical motion they had performed before onset — a welding arc, a lever pull, a component placement — without variation, without pause, without response to external stimuli. They were conscious. Their eyes tracked. They responded to questions with facial expressions that indicated distress. Their bodies simply would not stop.

Neurological examination of the first worker removed from the floor — a twenty-six-year-old named Kenji Abiodun-Strand — showed no abnormality. No seizure activity. No lesion. No toxin. No BCI malfunction. His motor cortex was operating normally. His voluntary control pathways were intact. He was, by every measurable standard, choosing to make the motion. He was not choosing to make the motion. He told the medical team, through tears, that he could feel his hands doing it and could not make them stop.

The loop persisted for between four and eleven hours across the seventeen affected workers, then ceased as suddenly as it began. Each worker stopped mid-motion, looked at their hands, and asked how long they had been doing this. None of them remembered the onset. The last thing each recalled was a sound — described variously as a click, a pop, or a "reset" — that they heard just before their memory stops.

Zheng-Dao's internal investigation attributed the event to "mass psychogenic response to workplace stress." This finding was accepted by the municipal health authority without independent review. The seventeen workers have been reassigned to non-fabrication roles. Three have resigned. One, upon being told the official diagnosis, laughed for a very long time and then said, "It wasn't stress. Stress doesn't have a rhythm."