Six centuries of Church-run tribunals get reconstructed from archives that were sealed until the Vatican opened them to researchers, including transcripts, trial records, and correspondence never before released to the public. The series follows the Inquisition from its origins hunting the Cathars in medieval France through its spread into Spain, Portugal, and the Americas, using dramatized reenactments alongside historians reading directly from the original case files. Individual episodes follow named victims through actual interrogation records, showing how confessions were extracted, how property was seized, and how the machinery of accusation could turn a neighbor's grudge into a capital charge. The film pays particular attention to the bureaucratic paperwork behind the terror, the notaries, scribes, and procedural rules that gave the tribunals their veneer of legal order even as they burned people alive. Scholars interviewed on camera argue over how many died and how organized the persecution really was. The documents themselves, handwritten and centuries old, are the evidence the series keeps returning to.