Daniel is working out the route of the knights and notices they make a perfect pyramid. Elsewhere, Vala wakes up and storms in to reveal she has the answer from a dream: the location of the weapon is on a planet with coordinates made up from those of the three planets they have. They immediately come up with one match.
SG-1 arrives at the indicated planet, whose inhabitants have technology similar to that from the Camelot planet. The locals mention that they're the second group and a Jaffa team passed through three days ago, led by Ba'al. The villagers direct them to the Parchment of Virtues for more information and warn that no one has ever returned from the quest alive. They talk to Osric, the keeper of the village archives, and tells of how there is a cave in an area cursed by Morgan Le Fay. He warns that the San Graal is protected by a dragon and only the most virtuous can triumph. Osric also has a map but refuses to show it to the, since Ba'al's group tried to take it.
Vala wants to steal the map but before they can come up with a better plan, soldiers of the Ori arrive in the village and take it as part of their crusade. SG-1 disguise themselves while the Prior has the villagers' books burned. The team take refuge in the tavern and Osric comes there as the soldiers are after him looking for the route to the San Graal. The soldiers have burned his map but he has the route memorized and can lead them. The team hides as the soldiers barge in, and then SG-1 shoots them down. They escape through a secret tunnel and Osric leads them through the forest to an area where a number of people and the local animals are frozen in time. Sam manages to find a path of real-time going through the field and everyone follows her, but her sensor malfunctions halfway through.
Vala deduces the answers must be simple since Arthur's knights got through. Throwing rocks, Sam leads them through the maze. They proceed through the words with Osric questioning their dismissal of the Ori's claims of godhood. They spot Ba'al sitting on a treasure chest, but they approach too close and enter a one-way force-field containment area. Ba'al explains he only had two of the three addresses and it took him longer, and his ship couldn't find it and he could only access the planet by Stargate. Ba'al's Jaffa took off after he became trapped and they haven't returned.
Daniel concludes that the test is a measure of the person's greed, and they must sacrifice something to the empty treasure chest. Each of them puts something into the chest although they have to force Ba'al to contribute. Once they collect everything, they're free to go on. They prepare to shoot Ba'al but he notes he has the name of the dragon protector and they have to take him with them.
They find the cave entrance and then Mitchell confronts Osric – they noted he gave away several hints that he's with the Ori. "Osric" fades away to reveal that "he" is Adria. They conclude everything was a set-up, including Vala's dream. Adria plans to secure the device and tells them they can work with her or she'll kill them one by one. They have no choice but to work together in the hope they can dispose of Adria later.
The group finds a metal plaque directing them to find the path that is "just and true." They hear a child crying down one path and when they catch up they find him in a cage. They convince Adria to free him, revealing the right path. They continue into what appears as a dead end and find another series of riddles. They solve each one riddle and the last one stop the quake. they proceed and find themselves confronting a wall of flame as the passageways close behind them.
While Ba'al mocks Adria's inability to get past the fire wall, Daniel concludes that they need to display is faith. So saying, Daniel steps right into the wall of fire… and beyond. It immediately disappears and they find a bridge over a bottomless chasm. Both Daniel and Adria cross over and Adria insists that Daniel should take the device. Daniel concludes that Adria is unable to lose her powers because of Morgan Le Fay's precautions and only her pendant provides her with any defensive powers. Daniel calls her bluff then takes the device… but it's an illusion. The cave rumbles again and he and Adria flee across the bridge, but the passageway seals over behind them. they look on in horror as a dragon flies up out of the chasm and unleashes a gout of flame at them…