Meglos

On the planet Tigella, the mysterious source of all power, the Dodecahedron, is failing. So Zastor, the leader of the planet, decides to call on an old friend – who travels the universe in a blue police box – to help them.

Meanwhile, on the nearby dead planet of Zolfa-Thura, a rag-tag band of space raiders form an uneasy alliance with the cactus-like alien Meglos. Their first goal is to prevent the Time Lord from arriving on Tigella.

Aboard the TARDIS, the Doctor, Romana and K9 find themselves trapped in a Chronic Hysterisis – a time loop that keeps them running through the same few moments again and again and again. Double trouble awaits them if they ever get to Tigella.

• "Meglos" is another one of those quiet sleepers.  I feel that this story is much better than general Who fandom lets on.

• A rather special guest star playing High Priestess Lexa is none other than Jacqueline Hill (who originally portrayed the First Doctor companion Barbara Wright).

• One popular tale that has drifted down over the years involves actor Bill Fraser (who played General Grugger).  Apparently he agreed to play the part only if he had the honor of being really horrible to K-9 (in this case kicking him) in a scene.  Apparently the actor disliked the metal dog.

• Kudos to the make-up artists on this story for transforming Tom Baker into the cactus-like Meglos.

• The end of this story links into the next story "Full Circle" thus beginning the E-Space trilogy.