The secret of the profession

One day, I was in my office. I was looking for a specific document or important paper at work, so what happened?

I opened one of the drawers, I found written on a piece of paper, its color compared to the rest of the papers, it was yellow, and it was very old, and it was written on it in a very clear handwriting, similar to the line of paintings. This is different from the secret of the profession.

And I found this paper disappeared, and I found myself in a completely different place and time, and I found myself in a strange place like...