I came away from the first season thinking that Nina was "a" mole, but working for someone other than the main antagonist for that season, essentially keeping track of both CTU and the would-be presidential assassins. I thought the people who had kidnapped Jack's family were not associated with Nina because they ordered him to kill her at one point.
I see from this document from Fox that Nina was working for the main antagonists. It explains some of the seeming plot holes as different operatives not knowing of each other's existence, and having no responsibility for the other operative's success or failure.
- Richard Walsh warns Jack, "Don't trust anybody, not even your own people, Jack."
Early in the series, Richard Walsh gives Jack a keycard and tells him
that whoever's electronic signature is on the card is the dirty agent.
Nina's signature is on the card.
When Jack confronts Nina about the keycard, she deflects his suspicion
by pointing out that she was with him in Santa Barbara (during their
affair) the day it was last used at CTU headquarters -- and therefore
someone else must have used it that day to set her up.
In fact, she altered the date on the keycard to cover her tracks.
- The dead shooter's thumb (cut off by Jack in an early episode) yields no I.D. CTU speculates the only explanation is that "either
this guy doesn't exist or else he has some friends in very high
Nina erased the records from the database.
- Nina calls Teri in the car and tells her that the dead body Jack found was Alan York's, thus alerting Teri that the man she is riding
with in the car is not Alan York.
Nina was not aware of Gaines or the details of his plan, and thus did
not know the significance of the name Alan York, or that telling Teri
would tip her off that she was riding with the man assigned to kidnap
- Jack shoots Nina, per Gaines.
Nina and Gaines did not know of each other's existence. So, when
Gaines ordered Jack to shoot Nina, he didn't know she was on his side.
Nina wanted to deflect her own involvement by fingering Jamey.
Nina purposefully brings Kim and Teri to the safe house, essentially setting a trap for them to be recaptured. She then leads Teri to
realize that she and Jack were lovers, turning Teri against her and
giving her an excuse to leave.
Once Alexis is stabbed and taken into custody, Nina doesn't tell the Drazens.
Telling the Drazens about Alexis does not further her objective, which
is to ensure that Palmer is assassinated by the end of the day.
- The Drazens capture Kim as she is being returned to the detention facility.
Nina told the Drazens where to find Kim, to provide them with leverage
to force Jack to kill Palmer.
- The Drazens want Jack and his family dead. Why doesn't Nina just kill Kim and Teri when she has the chance?
Nina's objective is Palmer's assassination and not the deaths of
Jack's family members.
- Nina helps Jack loyally throughout the season.
Nina knows that she is more powerful with Jack's confidence than