Caliphate is structured as a chaptered narrative documentary: reporter Rukmini Callimachi and producer/reporter Andy Mills follow a reporting thread that begins with a Canadian man's claim to have been an ISIS fighter and executioner, then widens into radicalization theory, ISIS's external operations, and its treatment of captives. Individual chapters bring in outside voices, such as former Al-Qaeda online recruiter Jesse Morton, to place the central source's story inside a broader pattern of jihadist ideology and English-language propaganda. Other chapters are built from on-the-ground reporting, including interviews Callimachi conducted with captured ISIS fighters inside a Mosul prison holding roughly 700 detainees, and a phone call with a Yazidi survivor of ISIS captivity. The series later pivots to a self-examination format: after Canadian authorities charged the central source, Shairoz Chowdhury, with perpetrating a terrorism hoax, the show aired an interview episode in which NYT executive editor Dean Baquet and investigative reporter Mark Mazzetti describe how the paper's re-reporting found no corroboration for his claims and where the original editorial process broke down. Re-released chapters carry an on-air correction note flagging the source's unresolved credibility. Listeners are typically drawn to the show for terrorism and radicalization reporting, war crimes documentation, or journalism ethics and verification practices. It functions both as a case study in investigative methods — document collection, open-source identification, source vetting — and, in its later episodes, as a case study in how those methods failed. Production is reported and narrative rather than panel or talk-show format, built around Callimachi's own recorded fieldwork. It is a limited series of 13 episodes rather than an ongoing show.