Neal Stephanson's epic Baroque Cycle is either a trilogy that concludes with this book, or a nonology for which The System of the World provides three volumes—one in which the "final" volume, Crytonomicon, was the first published. Either way, Stephenson has written a complex network of story-threads, which he deftly gathers in hand in this book, to finish with a hefty braided hawser.
The voyage from Massachusetts to London on which Dr. Daniel Waterhouse sets out at the beginning of Book One, Quicksilver, ends with his stepping onto the London dock at the beginning of System. He has a multitude of daunting assignments in hand: reconcile the feuding philosophers Newton and Liebnitz; create a coding machine to use the Philosophical Language as the "program" for a Logic Engine for Tsar Peter of Russia; organize investment for the Newcomen engine—and find a non-Alchemical use for the Solomonic gold packed in the bilges of a certain cargo ship.
Waterhouse is not the only thread-holder heading for London, either. Peter Romanov, the Great Tsar, brings Baron von Liebnitz in his train. Eliza, Duchess of Arcachon-Qwghlm and Half-Cock Jack Shaftoe the Vagabond King also have gold-centered business in the city on the Thames. Eliza's young ward, Caroline of Hanover, perhaps soon to be Princess of Wales, is determined to visit the city with Eliza's young son. The ear-chewing Charles White is headed for a confrontation with Jack Shaftoe's one-time galleymate Dappa. Marlborough, Bolingbroke, and Roger Comstock vie on the field of politics, as the central question of the day is yet to be answered: will Whig or Tory triumph after the death of Queen Anne? Will the next King of England be French Catholic James Edward or Protestant German George?
Of course, we know from history how this question was answered, but Stephenson's tale rests on simpler matters. As the diverse elements of this world engine are assembled, the final output of the machine is not half so wonderful as its clinking, clanking roar. And as with Newcomen's engine, Dr. Daniel Waterhouse is the midwife-cum-investment broker who will bring the thing to life.
The three volumes of the first book, Quicksilver, were illuminated, networked, shot through with references to mercury: quicksilver, the symbol of communication and science (Natural Philosophy, as it was then called). The mercuric systems in that novel presaged the coming system of the world. In the two volumes of the second book, The Confusion, gold became amalgamated with that mercuric essence, as the strangely heavy treasure from the Solomon Islands became the property first of Vagabond Jack, then of an island queen. In the same way, Eliza's path mingled the quicksilver, Apollonian air of the German court of Hanover with the Dionysian, golden streams from the French court of the Sun King, Louis le Roi.