My biggest complaint with these books so far has been that the Guardians of the gems haven't been very present. They just show up and then get killed/disposed of pretty easily. The Shifting Sands though, boy howdy. The Hive are some cosmic horror nonsense to the highest order and I'm 100% here for it. Once more, I'm asking Emily Rodda to make a teen/adult fantasy series in this universe.

I also really liked the bits not in the Sands themselves, though I did feel that this one suffered a bit from lack of identity. Like, there's the desert of course, but the rest of the surrounding countryside and Rithmere don't have as much personality as the plains of Opal territory, the hills of Ruby territory, or the fields and forests of Topaz territory. This is a minor gripe though.

I ADORE the sand beasts in this. Absolutely stellar creature design.

Final bit of something to add, my copy that I bought second hand apparently once belonged to a juvenile detention center.