Hi, Hetty!
Audrey and Heller first appeared way back in Season 4. Jack worked for Heller, who was Secretary of Defense at the time. As the season began Jack and Audrey were already in a serious relationship.
IIRC, at some point Audrey and her dad were kidnapped by terrorists and Jack rescued them.
In Season 5 (the BEST season of 24, with #4 being a close second), Audrey worked for CTU with Jack (I think). Heller was out of a job but still very influential (overbearing) in that season. At the end of that "day", Jack was kidnapped by the Chinese.
In Season 6 (the WORST season of 24), Jack was returned by the Chinese after being tortured for a couple of years. When he got back, he learned that Audrey had gone on a solo mission to China to rescue him. Of course she was captured. The ChiComs couldn't stand her either and dumped her back in Heller's lap. As Day 6 ended, Jack barged into Heller's home and--at gunpoint--had one last visit with comatose Audrey.
That's the last we saw of either of them until this season.
I’m an American, get out of the way!
Thanks for your refresher course on the Hellers. When was it that Audrey was walking along in her white dress or coat, dripping blood from her hands? I have this vision but I don’t remember when that happened.