Wersching previously had worked together with 24 crew members on a failed television pilot titled Company Man.
[1] She was cast for the part of Renee Walker a week before filming began, saying that "they spent a long time trying to figure this role out.
"[2] "The story is being told from her point of view," reveals the show's executive producer, Howard Gordon.
"[3] Throughout the series, Renee is portrayed as tough and strong-willed and has been shown to disobey orders or push the limits of the law when she believes such actions are necessary.
In the series, Renee is introduced when she pulls Jack Bauer out of a Senate hearing so he can advise and aid the FBI in tracking down Tony Almeida, who has been involved in terrorist activities.
Jack deliberately shoots off-center, only grazing her neck, but is forced to bury her alive as she plays dead.
[7] She temporarily dies, only to be resuscitated by Bill and Chloe, who explain the situation and the need for her to remain "dark" from the FBI and bring her into their operation.
Renee convinces Jack to trust Larry Moss for help tracking Edward Vossler.
Renee and Jack meet at Dubaku's hideout but are unable to prevent Taylor from being shot and seriously wounded during the rescue attempt.
When Juma and his men leave, Renee jumps to their boat, where she discovers their target to be the White House.
[15] During Juma's siege of the White House, Renee and Larry helped coordinate rescue operations and counterattacks.
Afterward, she debriefs Jack back at FBI headquarters, and both of them help coordinate the subsequent raid on the Starkwood compound and Almeida's search for the bioweapon, eventually resulting in its successful destruction.
Renee also encourages Jack to try the experimental procedure suggested by his doctors; using a sample of genetically compatible stem cells from a close relative may cure him of the pathogen's effects and save his life.
When Kim calls looking for her father, Renee explains the situation to her without Jack's knowledge, upsetting him and causing an emotional clash.
Renee is inside the abandoned building wired with explosives by Galvez when it explodes, but a warning from Jack saves her.
Renee arrives to find Kim safe after chasing a surviving operative into a parking garage.
She is summoned to CTU because of her unique knowledge of the Russian Syndicate in New York after having worked as an undercover agent in their ranks six years prior.
Brian Hastings, the current director of CTU, requests that she resume her undercover identity to set up a competing buy for the nuclear fuel rods President Hassan's brother is attempting to procure.
Unhappy with her decision to go back undercover, Jack attempts to convince her that she is too mentally fragile to handle the operation.
Despite her inability to return to a normal life, and recent suicide attempt, Renee decides that she will indeed agree to go back undercover.
After Jack fails to dissuade Brian Hastings from allowing Renee to go back undercover, he volunteers his field experience as her partner in the operation.
The initial stage of the operation involves locating the head of the Russian Syndicate in New York, a man named Vladimir Laitanin.
Renee visits an old accomplice in the mob, who is presently on parole, to convince him to take her and Jack to Vladimir.
After a brief conversation with her contact, he declines to help her because of the monitoring device attached to his arm, which is part of the conditions of his parole.
She then proceeds to place her contact's arm in a vise and without warning removes his thumb and the device with a nearby power saw.
Laitanin apologizes for the late hour before announcing that he has a business proposition regarding nuclear rods newly on the market.
Jack figures out that they are setting Renee up to have her take the fall, and he busts into the interrogation and chokes the DoD woman, throwing her against the wall.
Shortly after talking with Chloe and being informed that Samir (who executed Hassan) has died, Renee says that she recognized one of the EMTs as possibly being part of the Russian crime ring she infiltrated years ago.
He had planned to assassinate President Yuri Suvarov before being talked out of it by Chloe O'Brian, who told him that Renee would not want him to do this in her name.
"[18] NY Post journalist Jarret Wieselman said Walker's clothes never "looked sharper or sexier" on any other character.