Identity

"Identity" is the eighteenth episode of the fifth season of Stargate Atlantis.

Synopsis
Dr. Jennifer Keller's body is inadverdently taken over by a cunning thief, Neeva Casol. While Neeva tries to escape Atlantis, Keller finds herself imprisoned with a death sentence on another planet.

Plot
A woman, later identified as Neeva, is standing in a hallway in Atlantis dressed in Dr. Keller's jumpsuit. She appears disoriented, and stumbles into a lab occupied by Dr. Zelenka. He asks her if she is looking for Rodney, and she replies by asking where she is. Believing her to be ill, he takes her by the arm and attempts to lead her to the infirmary. She grabs a pair of pliers and stabs Zelenka, severely wounding him. Noticing her reflection in a nearby mirror, she stops: she is in Dr. Jennifer Keller's body. Leaving the lab, she encounters Rodney, who asks why she hasn't been answering his calls. They are then both notified that Zelenka has just been stabbed, and that they need Dr. Keller to perform surgery. Neeva gets into the Operating Room, and requests that the other doctors handle it, as she feels ill and "needs to lie down". Rodney comments to Ronon that it looked almost like she had never held a scalpel before.

Neeva is visited by Ronon, who is growing suspicious of her. Later, Carson Beckett examines her, stating that she has nothing physically wrong with her, and appears to be suffering from a psychological ailment. Neeva sneaks out of the infirmary and finds her way to the Puddle Jumper bay, hoping to leave the city. She finds a handgun and pockets it, and unable to activate one of the ships, she is caught by Rodney McKay. She tries to seduce him into taking her for a ride, asking him to take her to the mainland, but he resists. Still believing her to be Jennifer, he tries to get her back to the infirmary -- but she pulls the weapon and threatens to shoot him. Ronon appears at the back of the Jumper and stuns her with his gun.

"Dr. Keller" is moved to an observation room, and the team discusses possible reasons for her behavior. Woolsey suggests that their might be an entity that has taken control of her, and Rodney states that he could see in her eyes that she would have killed him. The team goes down to the room, where they manage to persuade Neeva to admit that she is not Dr. Keller. She and her accomplices were stealing ancient artifacts on a different world when she suddenly found herself in Dr. Keller's body. Rodney is able to cooberate her story by checking an SG-1 report detailing the Intergalactic communication device. The team decides to attempt to find Neeva's body, which they believe contains Keller's conciousness. They plan to also shut down the device to return each woman to their proper bodies. In return for information leading to the world, Neeva demands that she and her accomplices be freed, along with a puddle jumper. The team refuses to grant her a puddle jumper, and Neeva reluctantly agrees. Meanwhile, Keller finds herself in Neeva's body, and is arrested by the villagers. The Magistrate refuses to contact Atlantis for her, because Neeva is a known and cunning liar. As the team, discovering that Keller will soon be executed, closes in on her location, Neeva's accomplices, Jannik and Bordal, rescue Jennifer moments before she would be killed. The men don't realize that Neeva has traded bodies with someone, and treat Keller as their leader. They hide in a cave, where Keller makes them grow suspicious of her. They pull their weapons as Neeva, having escaped the Atlantis team, steps into the cave. The two women share a long look at each other in their bodies, then Neeva attempts to explain the situation to her partners. The two thugs are still suspicious, however they leave the cave, where they are ambushed by angry villagers. Bordal is killed, and Neeva, in Keller's body, is wounded. Jannik and Dr. Keller escape, and the Atlantis team discovers Neeva. They rush her back to the village, where Carson removes the bullet and tends to her. Meanwhile, Jannik catches up to, and pulls a gun on Keller, now believing that she is most definitely not Neeva. Back at the village, Ronon shoots the device and it is deactivated. Just before Jannik is to shoot, Neeva and Keller switch back to their original bodies. A gunshot is heard, and Keller wakes up in her body.

Back at Atlantis, Keller apologizes to Zelenka for hurting him, and he assures her that it wasn't her fault. Major Lorne finds no trace of Neeva, and she is presumed either dead or escaped. She is still a wanted fugitive on all Coalition planets, in the event that she ever does reappear. Rodney brings Jennifer flowers and chocolates, and he asks that she go with him on a picnic trip in a Puddle Jumper to the mainland. She agrees.

Background

 * This episode heavily references the events of the SG-1 episodes: "Avalon, Part 2" and "Origin".
 * The "parasitic organism" mentioned throughout the beginning of the episode is the parasite that causes Second Childhood. Rodney was infected by one and it is a valid theory as to what is affecting Jennifer.

Production

 * In the picture of Jennifer Keller's graduation, it appears as if her father is played by Carl Binder, the writer of the episode.