@xinfenkou6 You can find information about the types of UV at most scientific organizations such as the skin cancer foundation. It mentioned that in ordinary bathroom mirrors, the UV-A light is reflected just fine, but UV-B is attenuated, and UV-C light is absorbed by the glass. Also the reflectivity of various metals is indicated there.
@Scottish I see what you mean now that you mention it... I had it closer to Lovecraft but still not that, something else I can't quite put my finger on. And something about it puts me in mind of Resonance Of Fate 🤔