Now this was fun, giving you a glimpse into the mind of a sontaran as well as having a scared little blind girl for the kids to identify with.

Unlike the sycorax story as well, here everything just feels perfectly in character, the sontaran may end up helping the girl, curing her of her blindness, but he does so that she can avenge her parents, aid the quest he's on, and of course, show glory in battle. It works brilliantly.

I also love what they do with the rutans here. The idea of them being able to transform given some genetic material but their transformations being imperfect giving the misdirection of the girl being the rutan in disguise, but then it being revealed that it's the other sontaran, caught out by lack of knowledge on how the sontarans view their scars, it's great.