During their quest for the Sangraal, SG-1 must join forces with their enemy and face a real-life dragon.

The SG-1 team hadn't counted on a real dragon as a guardian until one flies out, breathing fire. However, Daniel thinks the Sangraal probably is a hologram. They escape, but the dragon follows them outside. Ba'al admits not to know its secret name, while Daniel believes that the name probably holds power over it. While they guess, Cam thinks of luring the dragon to blow it up, but the C4 barely impresses its digestion. Daniel makes it disappear by using Morgan le Fay's name in Ancient, Ganos Lal. They find it had guarded the frozen 'grave' of the realm's arch-magician, Merlin (or rather, Myrrdin). Vala accidentally triggers a mechanism which revives Merlin when she approaches an Ancient repository device. In the meantime, the team is transported to another planet via the obelisk by the gate outside. Sam surmises that the gate and obelisk are programmed to dial automatically every few hours and transport them to a set of planets that are cut off from the rest of the gate system. Unfortunately, they can't dial out to any other planets either while the program is operating. When he comes to, Merlin seems to confuse the team and Ba'al, with Arthurian characters, but once convinced they are on the same side, he goes to work with the Ancient device to create the Sangraal. Merlin dies at the device, wishing them good luck and referring to one last task. Ba'al's stargate programming skills now seem their only chance. Daniel tries the Ancient repository device himself, but is knocked unconscious. Meanwhile, Adria keeps searching for them via the stargate dialing program on different planets- each time a bit quicker- being one planet behind them. While she is searching, the team is once again transported to another planet, minus Merlin's body. Daniel awakens with valuable memories from Merlin and tries to construct the Sangraal using the repository device again, in exhaustingly intense phases, and finds it also gives him telekinetic powers. It also messes with Daniel's mind, having two different personalities and memories present (his own and Merlin's). Before he can finish the work, Sam and Ba'al disengage the dialing device, just as Adria's Ori troops arrive, allowing SG-1 to escape. Adria is able to capture Daniel before he can escape as well.