Title: Mainspring
Author: Jay Lake
Publisher: Tor
ISBN: 978-0-7653-5636-9
Rating: Excellent
Mainspring is the first book of the Mainspring Trilogy (the other two being Escapement and Pinion). Together they tell the story of Hethor, a clockmaker's apprentice, who is visited one night by the Archangel Gabriel and given a mission to find the Key Perilous and use it to rewind the mainspring of the universe, before the aforementioned universe runs down completely (at the time he is given the mission the universe is running about three seconds slow by his count).
Unfortunately, the reference to the Judeo-Christian God in this universe as the Celestial Watchmaker isn't just a metaphor. The Earth really is part of a collosal orrery, and orbits along a giant brass rack which interfaces with an equatorial gear taking the form of a 100 mile tall wall. At midnight people can hear the next gear tooth mesh with the rack, and certain exceptional people (our protagonist amongst them) can hear the workings of the internal clockwork of the Earth. If you travel far enough south you can see the rack stretching away into the heavens, and if you travel further south you can see the Wall itself, with it's brass-capped teeth.
Now you would naturally expect this obvious manifestation of great wonder will cause changes in the very concept of God, and indeed there are changes, but they tend to be minor. For example, Jesus was broken on an orrery rather than a crucifix, and clockmaking is considered a somewhat holy profession (creating in miniature what God wrought large). But interestingly, the philosophical ramifications aren't really that much different (at least to Western thought) to the Victorian era in which the novel is set. And it is this that adds an interesting dimension to the book.
Of course, if you are less interested in such matters, you still have a rollicking "steampunk" adventure tale, complete with military airships, a 100 mile high wall inhabited by all manner of strange creatures, and secret societies in a Victorian era where North America is still a British colony, and Britain is effectively at war with China. And a very engaging and well-written tale at that.