City Under the Sand marks the re-launch of Wizards of the Coast's Dark Sun campaign, after a 14-years hiatus.
While it's a fun reading, it's definitely much more enjoyable if you are very familiar with Dark Sun, and can leave you a bit puzzled if you're just beginning your travels through the deserts of Athas.
It looks like the author did his research, but not enough.
For example, metal is exceedingly rare on Athas, and while the plot revolves around retrieving a huge stash of steel lying in a city which has been buried under the sands for a thousand years (and that's fine, it's a good plot hook), metal weapons seem far too commonplace - lots of raiders and thugs are equipped with what most heroes should probably glance only once or twice in their entire lifetimes.
Another example - the book once mentions a bear. Too bad that bears simply don't exist in the setting.
The writing and the story aren't bad, but all of it seems a bit rushed, and presented more like a gaming module than a novel. Reading the book, in my mind I could clearly picture all the combat described in the novel as tactical encounters to unleash on my players...
Editing is definitely under-par. Lots of errors have crept in - probably the editor had been blinded by staring too long at the desert sun.
As I said, a rather fun read, but targeted at Dark Sun fans, not casual readers.