This is 'The Assassins & The Templars' episode of the Mystery Babylon series from 'The Hour of The Time' radio show, hosted by William (Bill) Cooper.
You might want to keep a pencil and paper at hand.
Try, if you can, to listen to all the lectures in order.
Otherwise you will fail to fully comprehend latter episodes .
It's hard to explain what it's all really about, but all you have to do to find out, is listen to it all in it's entirety.
You will not regret it.