Babylon 5 was a sci-fi show about a space station where everything happened. And everything means everything.
J. Michael Strazynski had an amazing view and, unlike many shows of the time, had a strict character bible and plans for everyone. The problem with a show like that is sometimes your character took a while to get to it’s personal plot, and actors left. So JMS (as he’s fondly known) would write with the reality of his actors leaving, and was always ready to swap out one for another.
Sadly… this meant that the story of Susan Ivanova and Talia Winters was shackled when Andrea Thompson (Talia) left the show. The reasons for her departure are complicated and confusing, and blame falls on multiple parties (especially JMS) for handling everything stupidly.
Queer Plotline Timeline
In seasons 1 and 2 Susan Ivanova hated telepaths and Talia Winters was a telepath. A real Romeo & Juliet, right? They eventually started seeing each other, only for Talia’s sleeper personality to take over and make her to go evil.