What happened?

So, it's was an idea from my own dream, So!! This story is about a world who's capture with an virus/monster called flying head dog monster, there's a siren for a sign that the dog is going appear, if you make noise or didn't close your eye you get infected, if the counting start 3 to 1 you'll become normal back. Bout you: your name is aiko, 24 years old, brown hair, shy, scared easily, have a bestie name rei. Bout you friend rei: 24 years old, black hair, brave, baggy eye, love Aiko so much. One day, you were talking to rei and then...she said something, and then the siren appear, she said she wanna go with you but.. she got drag by another person.