This journey began with a wizard walking into his door. Now it ends with a new kind of wizard standing on an Engine. Gazing down on this boiler from above, the wizard has the sense of being an angel or demon regarding Earth from Polaris. For, chastened by his failures, Mr. Newcomen has become most regular in his practices, and in this, his master-work, the seams and rivet-lines joining one curved plate to the next radiate from top center just like meridians of Longitude spreading from the North Pole. Below is a raging fire, and within is steam at a pressure that would blow Daniel to Kingdom Come ( just like Drake) if a rivet were to give way. But that does not come to pass. The steam is piped off to raise water, and the wasted heat of the fire affords a measure of comfort to the miners, and for the time being it all works as it is supposed to. At some point the whole System will fail, because of the flaws that have been wrought into it in spite of the best efforts of Caroline and Daniel. Perhaps new sorts of Wizards will be required then. But—and perhaps this is only because of his age, and that there’s a longboat waiting to take him away—he has to admit that having some kind of a System, even a flawed and doomed one, is better than to live forever in the poisonous storm-tide of quicksilver that gave birth to all of this.