It is probably safe to say that all people want to be a part of something bigger than themselves. Whether it is as harmless as brand loyalty to your favorite tech company or as dangerous as giving all of your life savings to a shady organization offering the promise of fulfillment, each of us has exhibited some cult-like behavior in our lives. What is it that makes the lure of history's worst self-proclaimed messiahs so attractive? The possible answers are many, but we ought to begin by studying the most peculiar and chilling cases and considering how rational people such as ourselves, sometimes by the hundreds or more, have been ensnared in the traps of deadly cults.