This novel is set during the Civil War in California, in this timeline the Civil War has gone on much longer than the history that we know. The main character is Blair Wilkes, a single mother, and the widow of a scientist that caused a horrible disaster. He created a machine to drill for gold, when testing it out he dug too deeply into the earth and released a terrible gas that causes things to rot and sickens people, killing them or turning them into "rotters".
The other central character is her son, Zeke. They are both outcasts because they are related to Leviticus Blue, the scientist responsible. Blair has not told her son about his father, and he becomes curious. Added to the shame of being related to the man that release the gas, many people believe that Zeke's grandfather, Blair's father, took a bribe from prisoners he held to release them before the gas hit the prison they were in. Mr. Wilkes releasing the prisoners added to their outcast status with the "respectable people", but earned them protection and respect among those that work in the underbelly of the city. He knows the only place he can find answers about his father, and grandfather, is in the walled off section of the city, so he enters this very dangerous place. Blair feels compelled to go after him.
The book starts a bit slow for me, but once they enter the walled city the pace really picks up. There are several moments when Blair and the other characters are being chased by zombies that are quite intense. The villain is a ego-maniacal, mad scientist which is always a fun addition. It was enjoyable, but it will never be one of my favorites. Though it was not marketed as a young adult book, it felt like one. This isn't necessarily a bad thing, it would be a well written YA book. If you are looking for an easy, but enjoyable zombie/steampunk book give this a try.
