Neuroscience and free will

If that were the case I don't think we'd get pondering about the question from physicists like these:

I didn't mean physicists, but physics itself. Anyway, I'll drop this issue.

I'm just trying to find out whether, in fact, there can be no worlds in which there are any necessitated events. If that is the case, then I wonder which agent is running computers?

Also, I can't help but wonder what stops the underlying agent from establishing automatic events. But perhaps that is a silly question.

~~ Paul