If you want to understand how the human body works, you can't just look at healthy humans. You need to examine the ill, so you can see how the body breaks down and where its weak spots are. And so if you want to understand how business works, it makes sense to look at financial fraud. After all, financial fraudsters work by getting to know a business really well, in order to take advantage of how it operates. That's the gist of our discussion this week with Dan Davies, the author of "Lying for Money: How Legendary Frauds Reveal the Workings of Our World." In our conversation, Davies shares with us his favorite fraud of all time, what all frauds have in common, and what people can do to avoid them.