Nyssa

Nyssa was the sensitive daughter of Tremas and became a companion of the Doctor, because the Master took over the body of her father, and then destroying her stepmother and her planet, Traken. She was transported by the Watcher to Logopolis, where her goodness made her susceptible to evil. Nyssa had to remain on Terminus after suffering the Lazar s' disease. There she used her technological nd bioelectronic skills to the cure of the Lazars and the Vanir.

Tremas was the Consul of Traken and was chosen by the dying Keeper of Traken to become the new Keeper. He married Kassia and her intentions were to imprison Tremas and she worked for the Master who took over control of her body.

Terminus was a hospital ship ituated in the middle of the universe. The ship housed the victims of the highly contagious Lazars' disease. It was run by Vanir and the Garm who treated the suffers in the Forbidden Zone. The Doctor discovered that Terminus was originally piloted by gaint aliens, and had started the creation of the universe by ejecting fuel into a void. Projected millions of years into the future by the blast, Terminus was on the point of repeating its error until the Doctor and the Garn it was stabilised.

Nyssa was in The Keeper of Traken to Terminus