We're introduced, in this episode, to one of the more adorable supporting characters in recent memory - Bellal. He's so little and helpful (and glowing) that from the first time we see him crawl out of a crevasse in the wall, we hope he makes it through okay and doesn't wind up dying horribly like that other "local alien who helps The Doctor and his companion, yet dies horribly in a Terry Nation-written Dalek story", Westar.
I absolutely adore Sarah's reaction upon meeting the little fellow. I can't tell if she's more scared or repulsed by Bellal, but her superb, jumpy reaction as he darts around her, trying to ensure her that he is on her side, is delightful. One has to remember that, apart from Linx in The Time Warrior, The Exxilons are Sarah's first experience with aliens, and Elisabeth Sladen brings Sarah's unfamiliarity with them to life in an unsurprisingly believable way.
The Daleks aren't that effective in this story thus far, carrying on from their first meeting with The Doctor in Episode Two. They do manage to outfit themselves with projectile weapons fairly quickly, but the only creatures they succeed in destroying are the odd few Exxilons. The strange root creature dispatches a couple of Daleks, and none of the remaining humans seem overtly in danger. One thing I do like about these Daleks, though? Their silver paint job, which would never be seen again after this story. I think it looks sharp.