Plot summary
Ron sought out a fundamentalist Mormon group that practiced polygamy. Their mother reveals to Pyre that there were two men named Chip and Ricky with her sons the night of Brenda's murder. The School of the Prophets encouraged a return to old and racist practices. Onias tells Ron he is their "One" chosen by God to receive God's revelations, which Ron believes. Brenda and Allen's marriage was on the rocks due to Allen's devotion to his extremist brothers. After he struck her, Brenda had asked the Church to grant her a divorce, but she was instead charged with saving the Lafferty clan from their ways.
When she attempted to do so, she was threatened by Dan and Matilda with blood atonement. Bishop Low and Brenda help Dianna and her children flee town for their safety, but Pyre worries Ron may have found and killed Dianna. Pyre breaks down as he confronts his now-wavering faith, reading the book Allen directed him to, Mormonism: Shadow or Reality?. Taba encounters Onias in the wilderness.
Credits
Adapted from Wikipedia contributors, Under the Banner of Heaven (miniseries). Series, exact episode number and English title matched. Paragraphs formatted; references and illustrations omitted.