About a week ago, you and your friends decided to summon demon

Nothing happened during the ritual, so you concluded that demons do not exist.

However, from that moment on you feel that something is wrong, you constantly feel that someone is following you... they are behind you at school, at home etc. you can't concentrate...

One day you are sitting at home alone, your parents have gone somewhere, you are doing your homework, when suddenly you hear a crash from the living room