Medical officer stationed at Atlantis in the Pegasus Galaxy. Following the death of Dr. Carson Beckett, Dr. Elizabeth Weir appointed Keller as interim chief medical officer until a suitable replacement could arrive from Earth. Keller herself was appointed the city's new chief of medicine.
Her first patient was Weir herself, mortally injuring during an Asuran attack on the city. She was forced to perform a radical procedure to stabilize Weir, and with help from Rodney McKay she eventually saved her life using Replicator nanite technology.
Jennifer is a small-town girl from Chippewa Falls, Wisconsin. The only family she left behind on Earth is her father; her mother died a few years ago. Jennifer continues to doubt her abilities -- though she is exceptionally gifted at what she does. Her new position in Atlantis, and her opportunities to travel off-world, continues to challenge her to push her limits and find out just what she is capable of.
As she continued to gain experience and confidence, Keller was responsible for finding a cure to the terminal condition suffered by Carson Beckett's clone, created by the Wraith Michael. This allowed him to be freed from stasis, and to resume a normal life. She also continued the original Beckett's pioneering work in Wraith genetics, using data acquired from Michael's own research to engineer a gene therapy that had the possibility of removing a Wraith's need (and ability) to feed on the life force of others. When the treatment was implemented, however, it had disastrous results -- proving that much more work still needed to be done.
Jennifer also struck up a romantic relationship with Atlantis's lead research scientist, Rodney McKay.
First Strike - Dr. Jennifer Keller is placed into the temporary position of chief medical officer of Atlantis, and is dismayed when she discovers Elizabeth Weir hopes to keep her there.
Adrift - Keller works to try and save Dr. Weir's life, performing a radical procedure to alleviate pressure on her brain.
Doppelganger - Influenced by an alien entity Keller has a horrid nightmare.
Tabula Rasa - Keller must care for the entire population of Atlantis when they are striken by a virus that causes amnesia -- and she herself is not immune.
Missing - Jennifer joins Teyla on an off-world visit to New Athos. But when they find the village deserted, the two must flee from a tribe of brutal warriors, testing the mettle of the hometown girl from Wisconsin.
The Seer - Keller cares for Davos, a gifted prophet who is going to soon die.
This Mortal Coil - A Replicator duplicate of Jennifer Keller helps a rogue group of Replicators create human clones of the Atlantis team, but is killed when Oberoth finds them.
Trio - Dr. Keller is trapped in an abandoned Genii mine with Carter and McKay.
The Last Man - In an alternate future, Keller and McKay return home to Earth after the fight against the Wraith takes a terrible turn. The two begin a romantic relationship, only for her to die from exposure to the alien virus she was fighting.
The Seed - Dr. Keller finds a cure for Carson Beckett's condition, and falls victim to a Wraith pathogen that takes over her body.
The Shrine - Jennifer fights to save her friend and patient after Rodney McKay contracts a virus that causes him to revert to a childlike state.
Tracker - While treating patients in an alien village, Jennifer is kidnapped and dragged through the woods by a Runner, who needs her help to save a young girl.
Brain Storm - Keller accompanies Rodney to a secret technology presentation on Earth, and is nearly killed when the weather-control technology goes awry.
Identity - A casual encounter with Ancient technology results in a body swap, as Keller wakes up to find her consciousness is in the body of a thief on another planet -- condemned to die for her crimes.