This is a terribly lazy story. And I'm a cat saying that! One of the few things about it that is not lazy is the way that here, on the first page, we see the Doctor explain to Adric (today being played by Eartha Kitt) about the device he will later use to solve the plot, instead of just pulling the device out of his pocket as and when he needs it.
On the other paw we here see the TARDIS console looking nothing at all like the TARDIS console usually does.
"Away with him, away with him! he speaks Latin."-to quote the Bard. It is surprising that Adric knows words of Latin, especially something like "isopterus". But maybe that is a Time Lord gift that the Doctor shares with him? I don't know. I'm only a cat; I don't even speak Latin.
"But they're huge - those mounds must be thousands of feet tall!"Clearly the budget couldn't support the drawing of huge mounds, but luckily Nyssa is there to tell us how big and impressive they look.
So they get captured by the giant termites and then meet a friend who gives them the exposition. His name may actually be Friend, since he is never called anything else in the rest of the story (another example of laziness).
I think Friend is being played by Lord Clark, presenter of the TV series Civilisation.
An interesting choice of guest star, and a typical example of the sort of stunt-casting that went on in Doctor Who during the 1980s.
Realising that there are only two more pages to go, the Doctor wastes no time in bringing out the gadget from page 1. It is lucky he had it with him, isn't it?
...And so they escape and that's the end of the story. Peter Davison couldn't be bothered to come back to be in the last picture, so they had to get Gary Lineker to stand in for him.
This is a particularly bad story - aside from the laziness I have already mentioned, it has inconsistent artwork and an absence of peril - the potential threat of the giant termites is squandered by them being dealt with so trivially, and they don't even reappear after the third page. It may be only 6 pages long but other stories have managed to make far better use of this limited amount of space. Awful. Mew.