Not only Kara returns to Earth to teach Clark 'a few lessons', but also she will be seen in the two-piece Supergirl costume.
The next episode of "Smallville" is named after the returning character, "Supergirl". Clark is stunned when Kara (guest star Laura Vandervoort) returns to Earth and tells him Jor El sent her to stop the dark force that is coming because he doesn't believe Clark can handle it.
Meanwhile, Lois confronts Gordon Godfrey (guest star Michael Daingerfield), a shock jock radio DJ who has been crusading against heroes, after he threatens the Green Arrow. However, after Godfrey is possessed by the dark force, he takes Lois hostage and Clark and Kara have to come to her rescue.
Vandervoort joined as Kara, Clark's Kryptonian cousin, in the seventh season and returned briefly in season 8. "You guys will get a lot of answers about where she's been and what she's discovered about her family. She's gonna teach Clark a few lessons", Vandervoort said on The CW Connect, adding a hint that one of the lessons is that of flying.
"Supergirl" airs October 8 at 8/7c.