!!!! Kara? What!?

[lithera]

"Covenant," the season finale, will air Wednesday, May 19 at 8 p.m.

Here's how the network describes the episode:

"Things come to a head in Smallville when Kara, a beautiful girl (guest star Adrianne Palicki) with superpowers, who claims to be from Krypton, comes to entice Clark (Tom Welling) to fulfill his destiny. Overwhelmed, Clark turns to his parents (John Schneider, Annette O'Toole) for advice but is shocked when Kara forces Jonathan to finally reveal the deal he made with Jor-El. Also, Clark makes a discovery that ultimately redefines his relationship with Lex (Michael Rosenbaum), and Clark's relationship with Lana (Kristin Kreuk) takes a final turn."