Iron Flame

I don't even know where to start

The Iron Squad, the fliers, the signets, Andarna?????
I thought I had lots of questions after finishing the last book but this one? I feel like Violet

I don't really know how to explain how this series makes you feel all the emotions the characters are feeling, especially in the last couple of pages when they were preparing, I was sooo anxious and then I cried and my heart broke and I stared into nothing for a good 10 minutes trying to wrap my head around that ending.