Incident Report #2199-4471. At 22:14 on June 2nd, I pursued a suspect on foot into Alley 7-C off Tier 4 of the Shelf district following a witnessed theft from a pharmaceutical vendor. The alley entrance is between two residential buildings. From the street, the alley appears to be approximately 3 meters wide and terminates at a back wall approximately 8 meters from the entrance. I have walked past this alley hundreds of times. It is an unremarkable dead end.

I entered the alley at 22:14:30. My BCI logged the entry. The suspect was approximately 15 meters ahead of me, which should have placed him through the back wall. The back wall was not there. The alley continued. I pursued. The alley continued. After approximately 45 seconds of running, my BCI's pedometer indicated I had covered 200 meters. The alley walls were still on either side of me, still 3 meters apart, still the same brick and concrete of the Shelf's residential structures. But 200 meters of alley cannot fit in a space that measures 8 meters from the street. I know this. I knew it at the time. I continued pursuit.

At approximately 200 meters, the alley opened into a small courtyard I have never seen. The courtyard contained a fountain — dry — and four doors, all closed. The suspect was not present. There was no exit other than the alley I had entered through. I turned and walked back. The return trip took approximately 10 seconds. My BCI logged the exit at 22:15:42 — a total elapsed time of 72 seconds, during which I covered approximately 400 meters in a space that measures 8. I returned to the alley entrance and looked in. The alley was 8 meters long and terminated at a back wall. There was no courtyard. There were no doors. There was no fountain.

I have filed this report against the advice of my supervisor, who suggested I attribute the incident to "perceptual distortion under pursuit stress." My BCI logged every step. My BCI has no stress response. The pedometer recorded 200 meters in. The GPS recorded my position as stationary — inside an alley 8 meters long. My legs carried me 200 meters. The satellite says I did not move. One of these is wrong. I do not believe either of them is wrong.