I is for... Ivo

Headman of a village on an obscure planet in the pocket universe of E-Space. Ivo and his wife ran a tavern, where they lived with their son. Above the village stood a tall tower, which was the seat of power of the "Three Who Rule". Ivo was forced to cooperate with the Captain of the Guards in the frequent selections which took place, when a number of the younger and fitter villagers were picked out to go to the tower to serve the lords. However, those selected were never seen again. Ivo understood that his son would be exempt from the process, but one day he was taken.

Ivo was secretly involved with a rebel group who were determined to overthrow the Three. He would pass on information to them about what the lords were up to. This group was led by an old man named Kalmar. He had amassed various pieces of technology which had been found in the area, and was attempting to get it all to work.

When the Doctor and Romana arrived on the planet, they helped with this - discovering that it belonged to a crashed spaceship from Earth named the Hydrax. At first suspecting that the Three were the crew's descendants, they discovered that they were in fact the original people, their lives prolonged as they were vampires. Ivo's son, and many other villagers, had been taken so that their blood would feed the Great Vampire which had hijacked the spaceship generations ago, and which now lay dormant beneath the tower (really the Hydrax itself). It was soon to arise, however.

The death of his son prompted Ivo to take more positive action and to join Kalmar's attack on the tower. The Doctor offered K9 to help with this, but Ivo was rather scathing of its abilities. He was proved wrong when it helped defeat the Three, and was forced to make a grovelling apology.

Played by: Clinton Greyn. Appearances: State of Decay (1980).

• Greyn returned to the show during Colin Baker's tenure, playing Sontaran Group Marshal Stike in The Two Doctors. Soon after he portrayed another Sontaran, Grand Marshal Nathan, in the Jim'll Fix It sketch 'A Fix With Sontarans'.