SG-6 has returned from a long-term undercover mission to P2X-885. The world is the third planet to convert to Origin in a month.
On Dakara, Yat'Yir informs Gerak that his visitor has arrived. It is a Prior, originally the administrator of the Ver Egen village on Celestis. Gerak says he has read from the book of origin and has found it is everything his people need. In time, all Jaffa will see Origin as their true faith.
Colonel Carter briefs General Landry on a project she and Dr. Lee have been working on with the information taken from the encounter with Khalek, Anubis's engineered clone. They believe the knowledge they have collected may be enough to create a weapon that will disable a Prior of his abilities. Later Carter returns to the lab to continue her work, unaware that she is being watched by a powerful presence.
Gerak goes before the council to share his opinion on Origin and his wishes to legislate the beliefs into law. Under his plan, all Jaffa children will be raised in worship of the Ori. Teal'c has heard the news and meets with Bra'tac, who admits that many of the council are old. Because the Ancients have done nothing, many will see Origin as the only way of truly achieving enlightenment.
Colonel Barnes of SG-6 has come down with high fever, chest pain and respiratory distress. He has been infected by a Prior plague.
Lieutenant Fisher listens to Lieutenant General George Hammond's speech at an air base, and before he can get near to meet him officers in hazard suits cram him into the back of a van and return him to Stargate Command. Soon twelve officers are infected, and only half have come in contact with SG-6.
Fisher, now in isolation, explains that he attended morning Prostration with Airman Ryan. A Prior was there and walked among them, blessing them. Apparently he was aware of the presence of humans from Earth, and made Fisher the carrier of the plague. This is why he himself is not sick.
Fisher stopped at a restaurant and gas station where he used a self-service pump. Not knowing how bad the damage is, Colonel Mitchell is sent into the public to help quarantine. IWN and other news sources are soon having a field day, as symptoms begin to sprout in Utah, Kansas and New Mexico.
Teal'c uses a M.A.L.P. to inform Landry of the updates on Dakara. According to his sources the council is swaying toward legislating Origin.
Carter and Dr. Lee are getting closer to an answer, but sleep deprivation is weighing heavily on them. When Lee goes to get coffee, Sam is alone. She hears a voice behind her and turns. A young boy stands where no one was before. "Who are you," she asks.
"I had no choice but to take this form. It's me. Orlin."
Lam confirms that he is human, and says the reasons he fell in the form of a child his plausible. A child's human mind can contain far more information for a longer period. He became a boy to preserve as much of the Ancient knowledge as possible.
In a briefing, Orlin reveals the truth about the Ori. Their offer of ascension and enlightenment is entirely false, because if they were to ascend their believers, then they would have to share the very energy they consume from them. Every believer who has given up his or her will to the Ori transfers their life force to the ascended beings. Only large multitudes of followers generate a detectable energy transfer. Orlin informs them that the Milky Way galaxy succumbing to the Ori would tip the balance dangerously in their favor.
Gerak meets with the Prior, who instructs him to travel to Chulak, where Teal'c and other dissidents are convening. He is to offer Origin to them one last time, and if they refuse, Chulak will be annihilated. Despite the pleas from Yat'Yir, who last a cousin on Kallana, Gerak intends to carry out his mission.
Orlin intends to use what is left of the Ancient memory of his mind to construct a viable cure for the Ori plague using Earth computers. Unfortunately a toaster will not do the trick. His task will be far more complicated than constructing a miniaturized Stargate.
Carter and Orlin go to the commissary for lunch, where the fallen Ancient explains that despite his appearance, he still has his feelings for her (though human social conventions will prevent them from sharing those feelings). Soon Orlin begins to repeat his conversation topics, and Carter realizes he is not making jokes. Something appears to be wrong with his mind.
There are now five thousand confirmed cases of infection, with the bulk being in the Colorado Springs and Denver areas. Eight have died, five being S.G.C. personnel. The number of fatalities will rise quickly.
There is a speck of good news, however. Dr. Lee has completed the anti-Prior weapon. With intelligence from the Sodan, Mitchell and Dr. Jackson will lead a team to P9G-844 to capture the original Prior who spread the illness on 885. Orlin believes the root D.N.A. code will help him finish building the cure. Now with the anti-Prior weapon, they may just have a chance.
Gerak warns Teal'c and Bra'tac that he will not hesitate to destroy the countless innocents who continue to remain free and independent, but at the last moment he is unable to use his ship to destroy them. Back on Dakara, the Prior is enraged at him. Still sensing Gerak's doubt, the Ori bring his mind to the city of Celestis, where he is given an audience with the Doci.
Lam shows digital readouts of Orlin's brain. His attempt to hang on to as much Ancient knowledge as possible is beginning to result in permanent brain damage.
Jackson, Mitchell and several military officers have arrived on the Sodan homeworld. Several minutes into their patrol they are captured by the Sodan.
Landry reads a report from the President's desk. Since the morning 8,000 people have become infected in 13 states. The President has ordered the country entirely under quarantine.
Ka'lel insists that no decision about the ratification of Origin into law be made while members of the council are missing. But a Prior arrives to ensure that all Jaffa will indeed bow down to the Ori.
The Prior is Gerak.