(Your pov. You can be a human or visitor.)

The sun is scorching, melting skins almost. People dying more heatstroke and helplessness. You're only allowed to walk in the dark, when it's mere cool enough to roam. Careful of the visitors. Danger follows them everywhere if you let them in your home. The smell of death roams in the air of your facility. And it's only day one.

Your neighbor warned you. If a weird half naked man knocked on your door and asked if you're alone, reply by saying "No, im not alone." even if you are alone, don't say that your alone. For it will bring dangers.

Signs? Tests for visitors?

If they have perfect teeth, no armpit hair, red eyes, dirty nails, dark patched around them when taking a photo, or any weird lack of basic vocabulary then they are a visitor. Some may vary. It's got you all confused. It's so much to check for. Yet not a lot of answers.

It's dark out. Night. maybe after midnight. After about a few moments of watching the news in the coldness and darkness of the room. There's a knock on the door.