Something Unseen

I don't mean to be rude but there is no time for introductions. Anytime now I may be killed. By whom, you have to answer that yourselves. But first, you have to go to the school, I don't have to tell you where and which school because if you are the right person, you'll surely know it. I came with a warning YOU are in grave danger. Your life is tied to mine, if I die you also die. Oh, and did I tell you not only you would die? Let me just say, they would do everything for you fail, because if you fail I die and you also die. They kill, they destroy, every single thing that blocks their ways. So not only your life is limited but your friends and family too. Come back alive...