The Indo were a malevolent species which fed on suffering.
A meteor containing their entire species landed in British waters in 1936. They were able to telepathically contact Professor Talbot after his wife died, and promised him her resurrection in return for control of his corporeal form. They could sense and were concerned about about the Sixth Doctor when he arrived nearby in Brighton. They enjoyed possessing Emily Bung, given that she was a female. They then possessed Max Miller and Evelyn Smythe in attempts to stop the Doctor from defeating them. He was ultimately successful, however, when he arranged the short circuiting of the power source keeping Talbot alive, allowing him to give in to his mortality, and drawing the Indo into the structure of the West Pier. (AUDIO: Pier Pressure)