Host Ira Glass reminds the audience about the old TV series MacGyver, about the guy who stops bad guys without a gun. He uses science and sheer ingenuity to invent solutions.

You can divide all living creatures into two camps. We humans are in one camp, along with lots of other things like dogs and birds and trees and caterpillars.

Susan Drury reports from Tennessee on a test that provides sudden truth from a stranger. It's based on a science whose goals could not be grander—to aid in the fight between good and evil.