I first thought that I was at a McDonald's.
Then I saw there were seats inside against the walls, like a waiting room. There was a glass door with a metal frame. I had come running. I had been fighting as some kind of magician with a magical sphere.
Outside, it was a dark-gray valley, and there were some aliens dressed in gray rags like Naz-Guls (like on the image below), and they were dangerous predators that hunted people. And there were people outside.
Through the glass door and wall, I saw people who sometimes came running. I slowly realized this was the only entrance from that dark valley.
When I saw them coming, I started opening the door, and closing it behind them. It didn't have a key lock, and it could very simply be opened from outside. I don't know why I was doing this.
I realized it was pointless, and felt unsafe. I knew the aliens were out there. I had seen them. I was with a few people, and when I started asking questions, I noticed one of them had "admin" access to the electric system controlling the door, so I told him to make it so it could only be opened from inside, which he did.
After that, I started looking outside, and any time I saw a person, I would poke my head out and call them. Sometimes they didn't seem to understand and I yelled louder, and sometimes they came. Sometimes I would yell in English and in Spanish, in case they just didn't understand what I was saying.
Ultimately, some people didn't come inside. And by the end of the dream, I was more a doorkeeper to a homeless shelter valley than to a dark valley haunted by demonic aliens.
I concluded that some people were just too far gone in their head that they ended up out there without being able to process language. I associated them with homeless people who sometimes seem to have gone a bit mad.
Near the end of the dream, a United States Army bus stopped near the entrance and I just opened it for them. And in came a bunch of people, all dressed in beige camo. I tried to talk to them but they were too busy with their thoughts, walking straight inside. They were pretty domineering.