This six-part story starts when the Doctor and co arrive at a Tibetan monastery in the Himalayas, and discover the monks there have been terrorised by a group of yetis. Naturally, all is not as it appears and the yetis are in fact robots being controlled by a disembodied intelligence, who is also controlling the abbot of the monks and one of the Doctor’s old acquaintances from a previous visit.
To be honest, I found it hard to follow exactly what was happening in this one. Four of the reconstructed episodes were particularly poorly done, with muffled sound, over-exposed images, no captions, and looked like they had been transferred from VHS (they probably had). Admittedly, I could have tracked down some better quality reconstructions, but I wasn’t all that interested in the story anyway. It dragged on for too long.
About the only thing I liked was the voice of the disembodied intelligence – slow and calm but really creepy. For a moment, I thought he might turn out to be an early form of The Master (since he referred to himself as the master), but it seems there was no relation after all.
The controlling machine is destroyed, seemingly taking the Intelligence with it, and the yeti robots are disabled. The Tardis leaves for hopefully warmer pastures.
In short: meh.