It was a fairly enjoyable read, hence the '3 stars', but I think 'The Obsidian Dagger' was better.
The first chapter was a bit 'over descriptive', in that the use of verbs and adverbs was kind of 'over-done'. You know how Stephen King said 'The road to Hell is paved with adverbs'? Well, I found the level of description went on and on and on in the first chapter. I got the impression that the copy editor had said 'describe more of the feel of old London town, the smog, the buildings, etc.etc.'
But by the second chapter it started to get more character based and the story began to unfold. We learn more about the Tseiqin in this book, who they are, their motivation, their history and fears. One of the Tseiqin, Lin Zi, actually likes some aspects of the humans, their dance's for one. And she even likes Horatio Lyle. I felt a bit more could have been done with that aspect, but her character certainly helped the book.
The Doomsday Machine is going to wipe out all the Tseiqin, so Lyle is working with them, and in particular with Lin Zi. The children, Thomas and Tess, play good supporting roles too.
Though I felt that The Obsidian Dagger had more action, intrique, dialogue, more of Lyle's science, compounds, and detective work. In short, more of a 'roller coaster ride' and a more intriguing read...
Verdict: An okay read, fairly enjoyable. But unlike The Obsidian Dagger, I wouldn't feel the inclination to read it again at some point, or to pass the book on to my niece.