The New York Times has introduced a documentary audio series that follows Rukmini Callimachi, who covers terrorism for The Times, on her quest to understand ISIS. Today, as a special episode of “The Daily,” we offer Chapter 2 of “Caliphate,” in which Rukmini speaks with a former ISIS member about how and why he joined the fold.

The next episode of “Caliphate” will publish in the series’s own feed on Thursday, May 3rd, and as a bonus installment of “The Daily” on Saturday, May 5th. New York Times subscribers can listen to that episode now at nytimes.com/caliphate.

This episode includes disturbing language and scenes of graphic violence.