Staying Human

The shockwave of the explosion resonated so deep in my body it felt as if the marrow of my bones would vibrate free from its skeletal cage. But that's getting ahead of ourselves, isn't it?
This is the story of your past, your present, and if all goes well...your future.
My name is Jack; I've lived for the past 500 years without knowledge of what or who I am, and now that I'm slowly finding out...it's not looking good.
There is someone...or something...that is guiding us to the brink of destruction and I seem to be the only one that knows about it.