Leela was supposed to be killed off in this episode. She was going to die defending The Doctor from the Sontarans. This was vetoed, as it was felt Leela's demise would traumatize younger viewers. Louise Jameson was unhappy with Leela's departure, as she felt she should have died a warrior's death rather than stay on Gallifrey with Andred, a character she barely knows.
The last appearance of Louise Jameson as Leela. Leela would be the last human companion not from contemporaneous time of when Doctor Who is filmed in classic Doctor Who (1963).
Leela's romance with Andred is undeveloped in the story. Louise Jameson was invited to continue her role. She was unsure whether she would stay until the end of recording, so a plot device had to be ready to allow her to stay on Gallifrey.
In the 2008 audio story of Doctor Who: The Companion Chronicles "The Catalyst", it was revealed Leela had survived the destruction of Gallifrey in the Last Great Time War and Leela had been captured and imprisoned by a warrior race called the Z'nai and they interrogated Leela for information on the Time Lords.
It was rumored that in Tom Baker's final season playing The Doctor, there was going to be a scene filmed which The Doctor briefly returns to Gallifrey to attend Leela and Andred's wedding, from which he sneaks away quietly.