Sister warning me of some danger

[DanaeM]

Hi! This is my new post although I've being using this page for a while to discover the meaning of my dreams. Today I had a nightmare that I can't really figure out the meaning for so I would appreciate if someone can help.

I was in a room, dark room I would say that was kind of foggie, I was standing up looking at my sister that was sitting down with her arms between her legs and her legs crossed. She was sitting on top of a bunk bed with her faced fixed on something in front of her , her eyes were lighting up like with fire and she kept saying, as if she was having a vision or smth "black magic" . Behind her was the number 76 hanging from a white wall backwards, surround it by a line of fire and when I got close to the wall I could see the number 2 backwards as well like being carved into the wall.
I woke up very abruptly and my general feeling of the dream was fear. I have never in my life done black magic, also I haven't talk to that sister for a while now.