In Civil War era Seattle, a steam-driven mining machine has run amok and opened a volcanic fissure that releases a zombifying gas. The damaged area is walled off, the inventor responsible disappears and his young wife is left to fend for herself. Years later Briar Wilkes toils in the outskirts of Seattle to support herself and her teenage son, Zeke. Determined to discover the truth about his father, Zeke crosses through the wall, and Briar follows close behind determined to save him. Inside the wall, full of poison gas and hungry zombies, they discover a community of dogged survivors living underground and in sealed-off buildings, including a certain sinister doctor who produces amazing inventions but exacts cruel prices.

Okay, so this is the first proper steampunk novel I've read in ages. Back when I read The Difference Engine, I'm not even sure it was even a thing. Anyway, frankly, this dragged. For a bog chunk of the middle, I just wanted it to be over. It didn't help that one of the two protagonists was a young idiot, your actual punk, and I kept wanting him to fall down a hole and die. I reckon if it had been a hundred pages shorter it would have been fine. It's tight, well, if rather plainly, written and the setting is fantastic. If anything, Priest's big mistake is in her restraint. A few more bells and whistles, or gears and cogs, added to the plot, to baroque the story up a bit, give it a bit more attitude, make the book a lot more ornery. A few elaborate secrets and mysteries, a few more gonzo characters and situations. As it is, it feels like she's carefully contained the necessary madness behind a high wall and won't let it out. Which is a pity.