10 Best Stargate SG-1 Guest Performances

In the seventh season episode Fallout, brief replacement character Jonas Quinn reappears on Earth to ask for help. His planet might explode soon and he's hoping to prevent it. When Sam Carter and Teal'c are helping him with his calculations, they meet Kianna, a brilliant scientist who has become recently involved with Jonas while working with him on the problem. They construct a massive drill and head down through their planet's crust.

It's only then, as the situation gets a great deal worse for them, that Kianna is revealed to have been a Goa'uld all along. She was sent here by Ba'al to assess the situation and she seeks to take advantage of it for herself. It becomes apparent however, that as the situation gets worse for them, her unique abilities as a Goa'uld are vital to the completion of the mission. She later confesses to Jonas that he's never interacted with her host, it was the symbiote that he fell for and who fell for him in return.

Kianna is probably one of the most intriguing Goa'uld in the series. While all of them are power-hungry and amoral, Kianna exhibits enlightened self-interest in helping the Kelownans. She confesses genuine feelings and is willing to lay down her life. A real shame then, that she only appears the once.