Jack is a very quiet and studious boy, he has lived with his family in Nueva York for a few years now
One night Jack woke up at dawn with a severe headache, he went to the bathroom washed his face and went back to sleep again
He got up again and this time the headache was stronger, suddenly he heard a voice in his head and it tormented him too much, that voice the only thing that repeated was:
let it out Jacklet it out Jack let it out Jack
Jack couldn´t take it anymore and began to bump his head against the wall, it was useless but he made the voice go away for a moment
it´s just your imagination Jack
the voice returned and Jack could no longer hold it was different, the voice no longer said the same but now it said:
i´m going to behead your family Jack
he couldn´t believe it anymore but he let himself be carried away, out of nowhere he ended up transforming into what the voice wanted, his true self, and so Jack ended up being a monster at night and a child by day, he beheaded everything he saw, Jack admitted what he really was and had no more to think and went down that path beheading humans heads.