Having failed so far to find the Sangraal on any of the planets uncovered by Daniel's (Michael Shanks) research, Vala has a dream that provides SG-1 with the information they need to locate the planet. SG-1 arrives at a medieval village and is told by the local villagers that another group has already arrived and set off in search of the Sangraal, and based on the descriptions, it's obviously led by Ba’al (Cliff Simon). The townspeople warn SG-1 that no one has succeeded in the quest to find the Sangraal. Undaunted, SG-1 goes to the village library and meets Osric, the keeper of the archives. Osric shows them the parchment of virtues, left by Morgan Le Fay for all those who seek the Sangraal, but Osric refuses to share the map she also left behind. However, when the Ori army arrives to convert the village and burns the contents of the library, Osric seeks out SG-1 and offers to help them find the Sangraal, having memorized the contents of Morgan Le Fay's map. SG-1 then encounters a series of obstacles and traps left by Morgan Le Fay to weed out unworthy seekers of the Sangraal. SG-1 deciphers a way through a temporal distortion maze, and then discovers Ba'al, trapped in a force field and abandoned by his Jaffa servants. Ba'al claims to know the name of the protector of the Sangraal, so they allow him to join them on the quest. And he is not their only unwanted companion. Osric morphs into Adria (Morena Baccarin), and forces SG-1 to take her along on pain of death. The unlikely group heads into the caves to pass the final tests and confront the protector of the Sangraal, or die trying.