Thursday, 1st March 1984 6:40PM BBC 1 (23 mins)
The Master has been declared a messiah by the Sarns and under his influence they imprison the Doctor in a sacrificial chamber. But why does the Master need Kamelion so much? Perhaps the answer lies in the small black box that Kamelion forces Peri to carry, but she could not have been prepared for what she finds inside it.