Unless Acted Upon By A Force: Part 1 of the Laws of Motion Series (фемслэш)

This series takes place after Season 4, and diverges from canon there. Susan Ivanova is now in charge of Babylon 5, and is shocked to find that, when the new commercial telepath finally arrives on station, he brings with him his wife, one Talia Winters.
Talia is herself, once again. But her memory is shattered by the events of the previous three years, and the work done by Psi Corps to remove the programmed personality. She has no recollection at all of her time on Babylon 5. But then certain places, and certain people, evoke flashbulb-type recollections that eventually lead her to seek help in remembering who she was.