Daniel, Vala, and the Ori Prior arrive on the "Planes of Celestus" at the City of the Gods. The two of them are left to wait. Another Prior arrives on a planet and announces "Hallowed are the Ori."
Back at SGC, Daniel and Vala's bodies are stable and Landry orders Lam to take whatever steps are necessary to break the connection if they start dying again. Teal'c briefs Landry on Gerak's rather shady background and Landry asks him to arrange a meeting with the Council's new leader. Daniel and Vala are exploring the Ori temple and determine that in their religion fire is a symbol of good. Daniel wonders how fire became a symbol of evil and wonders if the Ancients were responsible. Their Prior returns and warns the village has been corrupted. Daniel tries to explain about the Altarans/Ancients and the Prior want to know if they know of other "unbelievers." Vala and Daniel are both reluctant to help them or express much belief in these newest "Gods."
Landry asks Mitchell to check out a planet (the one in the opening) where a missionary arrived to preach a new religion. The missionary is performing miracles to prove his claims so Mitchell takes SG-12 to investigate. The Prior offers to let Daniel and Vala talk to the Ori but he tells them to merely speak and they will hear. Daniel asks for a meeting with the "Doci," their leader, and the Prior takes Daniel (but not Vala) to see him. Gerak arrives at SGC and isn't particularly welcoming.
Mitchell makes contact with the missionary, who acknowledges he knows of Daniel and that the Earthlings need the revelation of their destiny. Daniel is taken to the Doci, who knows all about him. The Doci warns that all that reject the path of enlightenment will be destroyed. At SGC, they trade war stories and proverbs but are uninterrupted by a nonscheduled incoming wormhole. Daniel believes the Ori are simply greatly advanced beings and is reluctant to believe the Ori asked the Priors to worship them. In response the Doci takes him to a great flaming pit and the fires fill the Doci. He speaks in a different voice and "he" states that the Ori plan to demonstrate their powers.
Mitchell and the Prior are the ones who were arriving, and Gerak expresses some interest as he believes there are those who will challenge their power. Daniel's host states that the Ancients, their enemy, hid the Earthlings from them before he reverts to "normal" and praises the Ori. Mitchell takes the Prior to Daniel and Vala's bodies and asks for him to perform a "miracle," but he declines. Gerak wants to challenge the Prior if he is preaching of false gods and they take him to him.
Daniel is escorted back to Vala and updates her, warning that the Ancient won't intervene. The Doci orders that they be sent back to the planet with the village so they can see how the cleaning will be enacted. Daniel thinks the artifacts Fannis found may be the key to defeating the Priors. Fannis arrives and Daniel suspects they were sent back to weed out the heretics. Fannis believes the risk to his life is worth what they might achieve and they all sneak out to examine the artifacts. He takes them to another communication device and they use the two stones they found at the house to activate it. On Earth, Daniel and Vala start to awaken but the Prior shows up, shuts down the device, and "miraculously" kills Fannis.
Daniel and Vala are taken back to the place of judgment and while sentence is pronounced on them, Lee informs Mitchell and Landry that Daniel warned them of the Priors before he went back into a coma. SG security draw guns on the Prior on Earth but he recovers his staff and uses it to burst into flame before disappearing.
Daniel and Vala are given the Test of Fire again and their bodies begin to go into shock again. Mitchell decides to use the Gate to send the communication device away. When it goes through the wormhole it breaks the connection just as they would have "died." The Administrator is brought before Doci who shows him the "flames of enlightenment" and the fires pass over him, turning him into a Prior. The Doci announces they will form an army and build Godships to spread "Origin" to all believers and the wicked shall be vanquished.
At SGC, Vala releases the bracelets on her and Daniel, and then they hold a debriefing and consider the nature of faith. Landry figures they're ready and the Ori should "bring it." Jack shows up to meet with a surprised Daniel and they go to meet with Mitchell. Jack has Mitchell take him for a ride in his fighter plane, the first since his incident, and Jack tells him he doesn't have to pick out his own team, he'll be getting SG-1, and Landry has said Mitchell's going to be fine.