I had a little trouble settling into Storm Glass because I only barely remember enough about Poison/Air/Magic Study to figure out how Opal (the lead character in this series) was related to Yelena (the lead character in that series.) Thankfully, Snyder gave me enough info that I could find my way through the story without having to stop and go find some sort of synapses for the other series.
So basically, if you liked Snyder’s series about Yelena – then you’re definitely going to like this one. There’s a lot of magic. A lot of trying to figure out what magic does (and doesn’t do.) A lot of secret-y stuff. And just enough connection to that first series to make you feel like you know the places these characters visit.
If you haven’t read Poison/Air/Fire Study – I don’t think you absolutely have to read that series, but I think it’s useful.
Now I’m off to read the next book in this series.