Genevieve Teague was one of the main antagonists in the fourth season of Smallville. She was the British descendant of Duchess Gertrude who learned that the witch Countess Margaret Isobel Thoreaux would try to to destroy the Teagues because it was Duchess Gertrude who ordered her to be burned at the stake. Genevieve was the mother of Jason Teague, a member of the Veritas and had an affair with Lex Luthor's father Lionel Luthor.
Genevieve and Edward were both in the inner circle of Veritas, alongside the Luthors, the Queens, the Swanns, and other powerful families. While her husband was devoted to serving the Traveler, Genevieve - as the heiress of Gertrude - was focused on acquiring the Kryptonian Stones of Power. These stones, which had been scattered across the world, had been sought after by her family for generations. Genevieve ordered her son Jason Teague to start dating Lana when she learned that Lana went to Paris, France. The reason for that was because Genevieve needed Jason to show Lana the tomb where Countess Margaret Isobel Thoreaux was buried since Lana was Isobel's descendant.
Genevieve immediately took an interest in Lana, who was connected to this mystery through her ancestor Isobel Thoreaux. Genevieve even arranged for her old boyfriend Lionel Luthor to be freed from prison to help locate the Stones of Power, something she and her husband Edward Teague were trying to find since they believed that the Stones of Power could help them find out more about the Traveler. Lana recognized Genevieve from a dream she had of Isobel being burned at the stake which made Jason believe that he was being manipulated by his mother into dating Lana which Genevieve denied.
When Jason started working for Lex Luthor after getting fired from Smallville High, Genevieve confronted Lex since she felt Lex was using Jason to get his hands on the stones and to avoid contact with Lana. Nevertheless, Genevieve was able to get Jason to help her kill Dr. Bridgette Crosby to collect the Crystal of Water. Genevieve only mentioned Clark a couple of times, and never found out that he was more than just a farm boy and Lana’s ex-boyfriend. What she knew about him must have come from digging into Lana’s past, since she never met him in-person.
Genevieve ordered Lionel to help her get the Crystal of Air and swore to send him back to prison if he refused. Lionel countered that by exposing Genevieve and Jason for murdering Dr. Crosby and poisoned her drink and denied the antidote unless she gave him the Crystal of Water.
Jason kidnapped Lex and Lionel, and he and Genevieve held them hostage in a cabin. The mother and son team tortured Lex to make Lionel give up the location of the Crystal of Water. Lionel tricked Genevieve into thinking he gave it to Lana stating she is the chosen one and Genevieve decided to wait for Lana to come home in her apartment at the Talon. Lana reveals the stone is in her purse, but quickly kicks Genevieve across the room, in an attempt to escape. Genevieve attacked Lana and started strangling Lana, Isobel reacted to the threat on Lana and gained possession of her body to kill Genevieve with the Element. Isobel then vanished from Lana's body and with the Mark present on her back disappearing.
- Considering that Patricia and Virgil Swan was murdered on Earth-2 by Clark Luthor, it is possible that Genevieve, her son Jason Teague, her husband Edward Teague) were also killed by Clark.
- Dr. Bridgette Crosby was originally intended to be the main antagonist in season 4.
- Genevieve and her son Jason are the main antagonists in season 4.
- Genevieve had a relationship with Lionel.
- It's hinted often by Lionel that Genevieve had an incestuous relationship with her son Jason Teague.