Kat'lanna was a native of Detrios.
Rebelling against the oppressive rule of the planet's rulers, Kat'lanna was jailed. When Chris Cwej was captured and put in her cell, she managed to trick the guard out of his keys. She released the other prisoners and escaped with Chris. However, they were betrayed when they reached the rebel base and turned over to Enros.
Other rebels freed Kat'lanna, and they were going to kill Enros while he was unguarded. However, having learned the true nature of the Miracle, she realised that since many Detrians now believed Enros was responsible for it, killing him would make the Miracle disappear.
The fictional energy that create the Miracle, though, could cause a great deal of damage throughout the galaxy, so the Seventh Doctor, Ace and Jason sealed off its source. The Miracle dissipated and she and the rebels killed Enros, with hardly any of his followers noticing. They used the Miracle's vanishing to help create a new outlook, to rely on themselves to save their planet. (PROSE: Head Games)