“Morpheus” is episode two of season ten of Stargate SG-1.
At the end of the previous episode, “Flesh and Blood”, Mitchell said they needed a new strategy, as what they were trying wasn’t working. Many of the ships available had been destroyed by a mere four Ori ships and Chulak had been attacked. The Ori are capturing worlds at quite a rate, and they’re being led by Vala’s daughter, Adria. So this is a bit of a statement of the obvious; they’re getting the stuffing kicked out of them.
The weapon Merlin devised to use against Ascended beings, the Sangraal, mention of which was discovered in “Arthur’s Mantle”, they had failed to find it in “Camelot”, although they had found the names of three potential worlds that Arthur and his knights had visited in their quest to find it. Now Daniel has discovered the gate address of one of them.
SG-1 find an abandoned village full of skeletons, and they also find mention of Morgan Le Fay. There seems to be something making people fall asleep. And stay asleep until they die.
Vala, meanwhile, before she is allowed off world has to pass a psych evaluation. Which she is studying for. Psych evals are not tests you study for.