Keep your arms and legs inside the cart because this book is a wild ride.
We follow Clayson Spangler, a 14 year old who is used to living off the land. Now, I thought this was going to be a post-apocalypse earth where everyone had been living underground for centuries, but it's actually that there's a separate society living alongside ours, and they don't much interact.
I found the worldbuilding fascinating and there's a lot in here to like, such as:
Metal affinity being the cornerstone of the magic or "craft" system.
People's levels in different craft determining what they can do with each, but they still need their smarts to overcome challenges.
Amazing underground cities with two separate cultures, one explored more than the other at this stage, and based on always moving on and the city's worth in people and their ideas rather than structures.
Now, the worldbuilding is fantastic, but I found it hard to connect to the MC, and while it was action packed it very much felt like a rollercoaster ride I was strapped safely into than a truly gripping narrative.
There's a LOT going on and I enjoyed the ride through this author's amazing world!