The Tunnel I Was Running Through

There was no one. I knew they were there though, maybe just waiting for me to let my guard down before pushing through after me. Needless to say, I didn't wait to find out if I was right. I just took off along the wet concrete trying to put as much distance between myself and my pursuer as possible. As I ran I started to notice a lot more of those weird cuboid structures. Only this time some of them were triangular, like little pyramids coming out of the walls, floor and ceiling. The others had at least looked like they served some kind of purpose but these new things looked almost completely random,. Like they were a glitch in a video games levels