The Sixth Doctor believes he's landed the TARDIS on Exar 3, but instead the Ship has been captured by the Debans, one of two warring species on the planet Belstar. Ranon, their leader, gives the Doctor no choice but to complete a task: go to the Nomed Zone deep within enemy Siros territory and retrieve a blue rock from the Crypt of Primo. Since the TARDIS is trapped by the Debans' Galactic Co-ordinator Intercept, the Doctor and Peri have little choice but to obey. Dodging the Siros' CP10 gunfire, they eventually make it to the blue rock, retrieve it, and return it without issue to Ranson. Honouring his word, the Deban leader releases the TARDIS, and the duo leave.