- For the companies named after the Tonska species, see Tonska Industries.
The Tonska were led by a Yed-Prior who lived in a stone citadel in the middle of Almaraqq. The Third Doctor believed the Tonska had none of the creativity or imagination of humans, stunting their social development. (PROSE: ...And Eternity in an Hour)
The Tonska cities were powered by cold-fusion plants. These could also be used in the making of bombs. They controlled temporal rifts to a degree, though they accidentally produced too much time spillage, damaging their own cities. (PROSE: ...And Eternity in an Hour)
The Tonska developed much like humans. Their technological development increased beyond their environmental capacities. They eventually developed space travel, mined out their moon and learned of the Time Lords.
At some point, Zaniah came into power as the Yed-Prior, likely by killing her competition. When the mobile temporal rift arrived on Alrakis, she took advantage of the panic it caused by killing all who disagreed with her and beginning a propaganda campaign to sway people to her side. She controlled the temporal rift to a degree and planned to use it to become immortal while her subjects would live for only an hour.
The Doctor and Jo Grant were sent by the Time Lords to deal with the temporal rift and intuition circuits of the TARDIS brought them to Almaraqq after Zaniah was in power. After they were accidentally separated, the Doctor tried to talk to the Yed-Prior and was forced to help her with her plans. Though the Doctor tried to patch up the damage they had caused, it was too severe.
Jo, on the other hand, was taken by terrorists who were trying to stop Zaniah. She used the TARDIS to help them smuggle a bomb into the citadel. She helped the Doctor escape. At that point the bomb went off.