The worst part was the silence after 20 minutes. The file's runtime, she realized. At exactly 20 minutes past every hour, the fog thickened until it was solid enough to touch, and through it she saw other people—flickering, translucent, walking through her walls as if they'd always lived there.

That was three days ago.

This response uses data provided by Google's Knowledge Graph Watch Borderless Fog

The file name was nonsense: borderless_fog_20.avi .