In his cover story for The Atlantic magazine, the journalist Graeme Wood puts the Islamic State under the microscope. What is it? Where did it come from, and what does it want? Wood argues that ISIS seeks to revert civilization to a “seventh-century legal environment, and ultimately bring about the apocalypse,” and it’s committed to killing vast numbers of people in the process. Wood joins us Monday to explore ISIS’s intellectual genealogy and to explain why it’s imperative the West better understand it.

Graeme Wood’s article “What Isis Really Wants” is the cover story of the March 2015 issue of The Atlantic magazine. Read it here.

Graeme Wood is a contributing editor at The Atlantic.