All these tunnels look the same to me.
Now this is more like it. A genuinely enjoyable slice of Troughton monstrousness the mystical nonsense behind the Great Intelligence as seen in The Abominable Snowmen earlier in the series is swept away and they are allowed to shine as a nasty monster. The set work is stunning and the story well paced. Its such a shame that the majority of this story is lost to the winds.
Making his second appearance in Doctor Who is Nick Courtney however this time he debuts as a certain Colonel Lethbridge-Stewart and does a fantastic job. Oddly he isn't the only UNIT regular to appear John Levine (Benton) also appears albeit as a yeti!
I have a second wind on my mad quest. Bring on Fury From the Deep.