Laws, Robin D. -- The Esoterrorists

Tiny RPG which introduces his "Gumshoe System", which I understand is the underpinning of the latest Call of Cthulhu edition. However, the introduction doesn't work. I read the thing and I still don't understand the trigger/clue/narration system. Maybe it's too simple and I'm staring at the trees, but if so, I need a better-spelled-out example.

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