Terry Gross

What motivates someone to become a terrorist? That's the question former prosecutor Ken Ballen set out to tackle when he traveled to Saudi Arabia and Indonesia to interview more than 100 Islamist extremists. "We've never sat back and said, 'Let's really understand our adversaries,' " he says.

In Boomerang, writer Michael Lewis tells the stories of the countries hit hardest by the 2008 financial crisis. He also profiles some people who bet against European governments and are likely to make millions if and when they default.

Several apostles affiliated with the movement helped organize or spoke at Rick Perry's recent prayer rally. A leading apostle, C. Peter Wagner, talks about the movement and its missions, which include acquiring leadership positions in government, the media, and arts and entertainment.