SG-1 races against Baal in the hunt to find the Sangraal, Merlin’s anti-Ori weapon, and comes up against a series of ancient trials.

When the team finds Merlin himself, they must help him complete the Sangraal weapon before Adria and her Ori forces can track them down.

The Jaffa take the fight to the Ori, using a genocidal weapon on their new worshipers and landing SG-1 in the middle of a war they can’t control.