Doctor Who Kinda

The TARDIS lands on the idyllic jungle world of Deva Loka which is being surveyed for possible Earth colonisation Deva Loka is already home to a race of apparent savages however a mysterious people with strange powers which have mentally unbalanced the members of the expedition To make matters worse an ancient enemy of the natives known as the Mara is intent upon revenge and latches onto Tegans mind as its bridgehead to victory