Episode 192 of "Stargate-SG1"
s09e18 Arthur's Mantle

Cameron Mitchell and Samantha Carter are shifted to another dimension, and wander Stargate Command invisible and unable to interact with others. Mitchell grows frustrated that he can do nothing -- including eating. But Daniel, who has experienced this himself before ("Crystal Skull"), suspects what has happened to them -- and looks for a way for Carter and Mitchell to communicate with them. Meanwhile, Teal'c leads Major Hadden and SG-9 to the homeworld of the Sodan, a group of legendary Jaffa with whom SG-1 made contact earlier this year (the upcoming episode "Babylon"). The Sodan use an advanced transporter system, which apparently allows them teleport all over the planet rather than living near the Stargate -- one of the ways they have stayed hidden from outsiders for centuries. Teal'c and SG-9 are able to use the transporters to seek out the Sodan, thanks to Colonel Mitchell, who previously acquired the codes required to use the teleportation network after winning the trust of the Sodan. They soon discover that the Sodan have been savagely attacked... there are Jaffa bodies strewn everywhere, and the village has been burned to the ground. Among the bodies they find Lord Haikon (Tony Todd), leader of the Sodan people. He is still alive but near death, since their attacker targetted and killed their larval Goa'uld symbiotes. Haikon's symbiote is dead, and Major Haddon hopes they can get him on tretonin in time to save his life. Later the transporter system is damaged, leaving Teal'c and SG-9 several months' journey away from the Stargate on foot. Hoping for a rescue from Stargate Command after they fail to check in, Teal'c sets out to track the one person they have learned was responsible for massacring the Sodan: Volnek, one of the Sodan's own warriors (first encountered in "Babylon"). Teal'c uses a Sodan personal cloaking device -- which makes them invisible to everyone but each other -- to try and find him. When he learns of the attack on the Sodan by the treacherous Volnek, Colonel Mitchell himself decides to use his new invisibility -- and invincibility -- to hunt him down.