Eye of Rassilon started from a perfectly lovely moment once when I looked out of the window on a full moon night. There was a cloud obscuring the moon but the cloud had a small hole in it and the moonlight suddenly shone through it and the effect was magical, like an eye opening in the sky. I used the idea to create the phenomena of the Eye of Rassilon.

I set it on Karn in order to describe the journey by an ordinary space shuttle in real time, and also to have some fun with the flora and fauna. The Lunar lake was a joy to describe, as well as the phosphorescent Lunar Pelis.

I don’t know who decided to name the planets of the Kasterborus system, but it is possible to find a list online. They are Demos, Gallifrey, Karn, Polarfrey, Kasterborus The Fibster. But beyond that there isn’t much to go on. So that gave me a free hand to make it up.

“It’s the Fibster… The sixth planet of our system. It has an erratic orbit that crosses the paths of Kasterborus and Polafrey and at this point every ten years it looks like a moon in the night sky of Karn. Except when it is behind the nebula.”

The ‘Face’ of Rassilon is obviously all things to all people. To Bolar Lundar it is his great-uncle Dvoratre. To his wife, Hesthor, it’s his great-aunt Romana. To Marion it looks like Colonel Saunders, founder of KFC. It was rather fun describing the ‘Face’ lighting up just as I had seen it in a much more mundane way on planet Earth. This was a very enjoyable story to write.

The Sisterhood of Karn, of course, come from the Doctor Who episode ‘Brain of Morbeus’. Karn was described as being in the same region of space as Gallifrey. Nobody said it was in the same solar system. But that’s a small matter. They were presented as a different species to the Time Lords. But here I have made them Renegade Gallifreyans who reject Time Lord society. It doesn’t contradict the TV version, but gives it a different spin.

And the prophecy of the elderly Sister is a sinister moment when the excitement is over. “Vessel of the Renegade!” Of course, we know what that means. Marion doesn’t.

http://tardis.wikia.com/wiki/Sisterhood_of_Karn

http://tardis.wikia.com/wiki/Karn

http://en.wikipedia.org/wiki/The_Brain_of_Morbius