These religious fanatics often combine a totalitarian political mindset with a belief in sacred prophecy that they are mandated by God to rule the world, and they must act now against their enemies because time is running out. In fact they believe that we are approaching the end of time itself, the literal end of the world as we know it. This worldview is call apocalypticism. Sketchy details are emerging that suggests one of the motives for the alleged suspects in the Boston bombing may have been a belief in an obscure and contested Muslim prophecy about the apocalyptic End Times. We may never know the full details of what motivated the Tsarnaev brothers, but if we want to understand the genesis of much Islamic terrorism by a small handful of Muslims around the world, a speculative tour of their apocalyptic worldview may help us design a more effective response.