“Metamorphosis” is episode sixteen of season six of Stargate SG-1.
The Russian team return to the SGC with a man who has news that the Goa’uld Nirrti is experimenting on people again in the attempt to make the perfect host. After the man dissolves (not a usual outcome that), SG-1, SG-3 and the Russians return to the planet to find the others that she has experimented upon.
They discover several mutated people who claim that Nirrti is helping them, and that their appearance is nothing to do with her experimentation. There’s a machine which Carter believes is of Ancient design, and it seems that O’Neill is a bit suspicious of the person who gave them the information. The mutants are not eager to be rescued and possess interesting powers.
When Nirrti returns, the teams are captured and experimented upon too.