Lakertyan System

The Lakertyan System was where the planet Lakertya was located.

The Sixth Doctor tried travelling to the Lakertyan System with Melanie Bush, but fled the system when he discovered deadly radiation present. This decision inadvertently allowed the Valeyard to defeat him later on because he did not know the Valeyard had bonded him to a pair of leeching Nathemus. He was forced to sacrifice his future as this incarnation of himself to turn the tables on the Valeyard. Because of this, the Sixth Doctor sent his past self a psychic signal to go to Lakertya regardless of the danger because he needed to kill off the Nathemus that had been secretly implanted in him by dying in the past before they had a chance to grow, and he came under attack by the Rani with focused beams of radiation fatal to Time Lords, resulting in his regeneration. (AUDIO: The Brink of Death)