The Accidental Creation of 13

The following transcript was found beside 13 in the Emptiness. . . . . :

I-I don't know how much time I have left.
My name is Tim Silverlance.
The raids by the machines have gotten worse, but when I found a small copper half-circle with odd symbols around the center they all seemed to focus on destroying me.
I ran, but soon tripped landing in front of a bizarre 'doll' with the number 13 written on it's back.
For some reason when the machines saw me with it, they seemed even more outraged than before.
They attacked me with even more fury than ever before, but somehow I managed to get away.
I'm now in an abandoned room. A few lifeless bodies are here as well.
I keep looking between the copper half-sphere and the doll, wondering why the machines seem fearful and eager to rid me of the two items, but I am unable to figure it out.
What could POSSIBLY link the two together?
There's a beast not too far from here. . . . .
If this is the last thing I say, If this doll and the half-sphere are the keys to riding the world of the humans' mistakes, I want to do my part, and, whatever the cost, find out how to end this nightmare.
If I could just figure out how ~

The transcript ended there, with the ink smeared across the page as if interrupted.