In Book One, by simple neccesity, much of the story had to be devoted to establishing the given circumstances of the world these characters inhabit, but here in Book Two the story is free to explore the inner motivations of the characters and the relationships between them. The action is constantly moving forward and as the events unfold and storylines begin to weave together toward the climax I found myself frustrated by every interruption, which was not always the case with Book One. Further - when there is discussion of the sciences that govern this fascinating world, I found the theories and concepts more intriguing than in Book One - and now they aren't spoken of simply as lofty concepts, now there is desparation and personal attachment (sometimes literally) for the characters to the concepts being explored.
The more I read this series, the more it captures my imagination.
"A Calculus of Angels" picks up two years after the events of "Newton's Cannon". To give a quick recap of what has happened before, this novel is set in the 18th Century, but one that is no longer recognizable as the 18th Century. Isaac Newton discovered something called philosopher's mercury, a substance that has allowed science to go into a entirely new direction and it truly did change the world. The heroes of our story are Ben Franklin, who is the apprentice of Isaac Newton, and Adrienne, a brilliant scientists struggling with the societal strictures of being a woman. Two years prior to "A Calculus of Angels" someone had called down a comet and destroyed London completely. There are forces in the world that are similar to Angels or Demons (depending on how you are looking at it) called the Malakim. They are part of the hidden powers that are permitting these wonderous scientific devices.
This brings us to the second novel (more or less). France no longer has a central authority after the death of Louis XIV. Tsar Peter the Great, of Russia, is marching his armies East to build an Empire. A delegation from the American Colonies is sailing to Europe to discover what happened (after the Comet hit, there were natural disasters and all contact with the continent ceased), and the delegation includes Cotton Mather, Blackbeard the Pirate, and a Choctaw named Red Shoes. Ben Franklin is in Prague trying to defend the city from an attack similar to the one that destroyed London, and he no longer trusts Isaac Newton. Adrienne is learning more of the Malakim and her journey takes her across Europe in into the circle of powerful men.
This is a difficult book to really describe because it is so complex. The series begun with a true history of our world, but with one event (Newton's discovery), it changed the entire landscape so that even while real men and women are in the novel, they are in entirely new situations that will shape the characters in ways that we could never have expected. While I enjoyed the first book, I feel this novel is where the series really begins to pick up. I had to force myself to keep going at times in "Newton's Cannon", but here I just wanted to keep reading to see what happens next (and also to figure out exactly what is really going on here). Greg Keyes does an excellent job of building this world and the strange twist on our own. I don't think that anyone should pick this one up before reading "Newton's Cannon", but I do feel that the quality has increased in the second book and I'm looking forward to reading book three (of four).