How did ISIS manage to take control of so much territory, imposing its will politically and inflicting an immense amount of damage? How should we make sense of its origins and evolution as an organization? And does a better understanding of the group enable us to anticipate what form it might take in its next evolutionary stage? This episode features a conversation about these and other questions with Craig Whiteside and Haroro Ingram, two of the authors of a recent book, The ISIS Reader.