Epic London Adventure!
Jack, his sister Sadie, and his mother all arrive in London to look for his father, who often travels for business but has been in an accident and is missing. His mother is so distracted that she tells the two children to stay in the hotel while she goes out, which of course they do not do. Sadie thinks that she sees their father and takes off, with Jack in pursuit. They end up at a lost and found on the tube line, where they meet Mrs. Hudson and then are assigned to Gwen, a teen clerk Jack's age. She whisks them away before they can get forms filled out, and soon people are chasing them and weird things are happening. It turns out that Jack is the 13th Jack Buckles, and his father works for the Ministry of Trackers, who are involved in a battle with the Clockmaker. The Clockmaker wants to get the Ember, which started the great fire of London, and use it to set fire to the current city. Clearly, he must be stopped, and Jack and Gwen are the ones to do it. Eventually, the reconnect with Jack's mother, and learn a lot more about the Ministry and his parents' involvement in it.
Jack is a great character, and I appreciated that he had some family sadness but was bound and determined to work past it and effect some change, rather than sitting around moping. Granted, he probably should have proceeded a bit more carefully, but what fun would that be?
Readers in the US might not understand all of the British history, but there is a fair amount of interest in the Great Fire of London and that time period in general, so working the genesis of the Clockmakers into that time period was really quite brilliant.
Probably the best part of the book was the underground city where Jack's father has been living. Since this is the start of a series, I hope that we get to spend a lot more time there when the second book comes out!