We begin in 1681, with a young Sir Isaac Newton discovering something called philosopher's mercury. This, possibly heaven-sent substance, is the key to manipulating the four elements. It allows for the transmission of vibrations into the aether, where various states and compositions of matter can then be altered. The story then moves up to the 18th Century, where England and France are still at war. Thanks to Newton's science, the world has such miracles as aetherscribers, a proto fax machine, kraftpistoles, which are lightning guns, and fervefactum devices, that can instantly alter the state of any liquid to their boiling point. Be it the water in steam-powered engines, or the blood in the veins of enemy soldiers. Things are going badly for the French, and King Louis XIV, the fabled Sun King, demands his philosophers create a weapon of ultimate destruction; code-named Newton's Cannon.

In Colonial America, a young Benjamin Frankin is apprenticed to his brother in the newspaper trade. Eager to get an edge over the competition, Franklin invents a way to tune his brother's aetherscriber, so that instead of being limited to receiving signals only from its twin, other conversations can be intercepted. One such tidbit includes complex mathematical formulae, which Franklin believes to be a conversation between English philosophers. There is a problem, impeding their work, which by chance he has the answer to. Only later, does it dawn on him that those he is communicating with might actually be the enemy. Oh, and someone else knows what he's up to, someone with a supernatural ally. Franklin is warned that if he doesn't stop his experiments, his life will be in danger. Meanwhile, in the court of Versailles, Adrienne de Montchevreuil is attracting the attention of a newly rejuvenated Louis XIV. But Adrienne is far more than a lady of the court. Her placing is the product of the political machinations of a hidden society of women, known as the Korai. Thanks to them, Adrienne is secretly a highly skilled mathematician. When she is set to work as the secretary for those commissioned to develop Newton's Cannon, she gradually discovers that it is a horror beyond anything imagined. The Sun King is quite mad, and if his plans come to fruition, more than a million people will die. The story alternates almost invariably between the adventures of Ben Franklin, and Adrienne de Montchevreuil's attempts to stop the world's first weapon of mass destruction. Fleeing for his life, Ben travels to England in order to seek out Isaac Newton and hopefully correct his terrible mistake. Adrienne conspires with the Korai and the French Secret Service, to try and kill the king. Unfortunately, this is no easy task, as Louis has the supernatural protection of a black angel, one of a Malakim. Along the way we also get to meet the pirate Blackbeard, bodyguard Nicolas d'Artagnan and the astronomer Edmund Halley.

Greg Keyes is fond of using a comic book technique, championed by Jack Kirby, in which sequences start with action to grab the reader's attention. When he's not doing that, we get the lead characters awakening after being unconscious or asleep, and then brought up to speed on what's happened by the supporting cast. Although occasionally feeling lazy, the technique works more often than not, and Keyes' plotting and dialogue are all well above average. There was always more than enough going on to make me want to read just a little more, and the frequent use of cliff-hanger endings to chapters provided further incentive. The one problem is a lack of depth with some important supporting characters. Only Crecy, the mannish, clairvoyant Korai agent whose visions have set the course of Adrienne's life, receives adequate development. By the end, some questions which I felt should have been resolved are left open, and the conclusion makes it seem unlikely that answers will be forthcoming. But, all things considered, Newton's Cannon is a very good read that is inventive and entertaining enough to satisfy most adult readers. More of an historical fantasy than alternate history, its difference lies in the use of fantastical alternate physics, and the underlying theme of manipulation by dark, inhuman forces. I finished reading sufficiently enthused to order the other three books in the set.