his control and change Kamelion's appearance from that of Howard. Kamelion tries to warn Peri of the Master but the Master succeeds in gaining control. She flees the TARDIS with the creature in pursuit as the rumblings of the volcanoes of Sarn gather ferocity. In the Sarn colony Timanov has damned the Unbelievers to be sacrificed to appease Logar and stop the tremors. They flee to a secret base in the mountains filled with seismological apparatus, which the Doctor and Turlough stumble across. The Doctor informs the Unbelievers that the tunnels, which have been their refuge, are volcanic vents which will soon fill with molten lava. It is also established that Turlough is of the same race as those who colonised the planet, and when the indigenous people see his Misos Triangle, they greet him as a second Chosen One. Turlough realises Malkon may be his brother and becomes even more worried when Peri turns up and mentions the Master. Another important figure in Sarn mythology is the Outsider, a promised prophet, and Kamelion, controlled by the Master, fulfils this role admirably. He convinces Timanov of the appropriateness of harsh action and when the Doctor arrives with the Unbelievers they are all seized for burning. However, Malkon and Peri arrive shortly afterwards and stop this, though not before Malkon has been injured. Turlough is aghast when he finds his relative has been shot and the Doctor presses him for as much information as he has on the strange circumstances of Sarn. It seems it is a long abandoned Trion colony planet, and that Turlough, a Trion, suspects some of his family were sent here after a revolution against the hereditary leading clans of his homeworld. He supposes his father died in a crash but that Malkon survived, while he himself was sent in exile to Earth, overseen by a Trion agent masquerading as a solicitor in Chancery Lane. Kamelion has meanwhile seized Peri and uses her to transport a black box into the control room of his TARDIS. It contains a miniaturised Master—the real thing—who has been transformed by a disastrous experiment with his trademark Tissue Compression Eliminator (TCE) weapon. The Master thus re-established the psychic link with Kamelion to gain the power of movement and has manoeuvred the robot to Sarn so that he can take advantage of the restorative powers of the numismaton gas within the fire mountain.