"SW Kelly," Elias whispered. Was that her name? Or a location?

The footage was grainy, shot from a fixed position in what looked like a narrow hallway. At the end of the hall stood a heavy wooden door. For the first three minutes, nothing happened. The dust motes danced in a shaft of pale light, and the slight hum of the camera’s motor seemed to vibrate through Elias’s desk. Then, the door clicked open.

The monitor went dark. In the reflection of the black screen, Elias saw the door to his own office—the one behind him—slowly begin to click open. If you'd like to take this story further, let me know:

He looked back at the screen. The video had reached its final seconds. The woman in the yellow dress walked toward the camera. As she got closer, the grain of the film seemed to merge with the air in Elias’s room.

Should the story lean more into or a technological mystery ?