Some friends were removing the carpet in the living room of their new flat in North Finchley and on doing so found one of these:
It's a seal of solomon hexagram, designed to ward off demons.
It was all professionally done, with the inner circle made up of chevrons, and all black and gold. Proper devil worship stuff. I have to say, I don't think I'd feel very comfortable with that in my house. They're laughing it off, but you can feel the despair.
Time to hire that sander.
Spooky.
