SG-1 and others SG teams a planet and find dozens of dead Jaffa, brutally massacred. They find Bra'tac who is in bad shape, and finally Teal'c, also injured.
The Jaffa are meeting and some speak out against the Ori. Bra'tac warrants caution while Teal'c notices a man striding through the camp. Teal'c goes after him but a tent explodes in the center of the camp.
Teal'c wakes up at SGC under medical treatment and discovers he's been unconscious for two weeks under Dr. Lam's care. She doesn't tell him that Bra'tac is in critical condition but SG-1 visit Teal'c and he demands answers. Teal'c remembers back to the explosion that rocked the camp and the panic that ensued, and insists on seeing Bra'tac. Bra'tac is in a coma.
Later Teal'c visits with Landry and reveals that the man responsible for the explosion was Ba'Kal, a Jaffa who works for Arkad, a traitorous Jaffa who plans to work with the Ori and struck against the Jaffa council to keep them from rallying against his masters. Landry refuses to send a team to investigate but Teal'c refuses to let it drop. Landry discusses the situation but admits there's nothing they can to do hold him. Teal'c prepares to leave and insists that SG-1 not accompany him. Teal'c returns to the village where the Jaffa Council was massacred and vows to find the coward responsible.
Daniel is watching over Bra'tac when he wakes up but he's still in bad shape.
Teal'c visits a bar on another planet and finds Lizan, a man formerly enslaved by the Jaffa who sold explosives to Ba'Kal, Arkad's man.
Bra'tac talks about how he knew Arkad and they fought in the past, then reveals that Arkad killed Teal'c's mother but Teal'c was still First Prime and couldn't go after him at the time. Colonel Reynolds checks in with a report that Arkad is working with the Ori and promising them he can bring Jaffa planets under their control and using weapon-grade naquadah to plan an attack on Earth.
Arkad's man Ba'Kal enters his tent only to find Teal'c waiting for him. Teal'c takes him out into the woods, removes his symbiote, and asks for information. When Ba'Kal refuses Teal'c leaves an explosive in his symbiote pouch and leaves, as the man blows up.
SG-1 discuss the situation and consider whether Teal'c is right, when Arkad contacts them and asks for safe passage to discuss the situation, offering to stop the attack he supposedly has planned against Earth.
Bra'tac confirms that Arkad fed them information but warns that nothing good will come of it. SGC agrees to the meeting and Arkad arrives and claims he opposed the Jaffa Council which he believes intended to enslave the Jaffa. He says there is a radical Jaffa faction that plans to attack Earth that launched the summit attack, and he plans to fight them himself. Arkad notes he has a huge fleet so that he wouldn't need to make a covert attack. He basically tells them to stay out of their way and they may work together in the future, but he still plans to embrace the way of the Ori.
Teal'c returns to the explosives supplier and demands more info. Meanwhile the IOA tell Landry to avoid confronting Arkad directly and stick to gathering intelligence. Landry sends SG-1 to find Teal'c and stop him at all costs, as he'll be perceived as acting on Earth's behalf and interfere with their negotiations.
SG-1 and SG-3 get ahead of Teal'c to the planet where Arkad is at and set up field generators and trip sensors to capture him. They wait for Teal'c but SG-3 misses it's check-in and Mitchell determines they're unconscious. Teal'c opens fire on Mitchell and warns them to get out of their way. Daniel tries to explain the situation but Teal'c continues toward the pyramid where Teal'c is. He then throws a stun bomb and takes out SG-1 except for Mitchell, who gets the drop on him. Teal'c disarms him and the two fight until Teal'c knocks Mitchell out. Teal'c then blasts his way into the pyramid. Teal'c is shot down and Arkad's remaining Jaffa take him before their leader. Arkad tells to leave then offers a staff for the wounded Teal'c to fight him. Arkad readily defeats him and talks of how Teal'c wiped out his family, defeated the Goa'uld, but now rejects the salvation of the Ori. Arkad boasts of how he plans to bring the Tauri to their knees. At that, Teal'c gets to his feet and after a brutal battle Arkad puts him down once more then draws his sword and stabs him through the chest. When he boasts of killing Teal'c mother, Teal'c kicks him back onto a metal point. Teal'c pulls the sword out of his chest and kills Arkad just as SG-1 arrives.
Teal'c is recovering at SGC and Landry reads SG-1's (falsified) report that the team was taken prisoner and Teal'c rescued them, killing Arkad in the process. Landry figures IOA isn't going to be comfortable with the situation. Teal'c vows to hunt down the other corrupt Jaffa and Bra'tac admits Teal'c is the son he never had.