The Revolution Business is the penultimate volume of Charles Stross’s paratemporal series The Merchant Princes, and it ends not just on a cliffhanger, but takes the reader over the edge. The pace has definitely picked up in this volume from the somewhat static middle volumes. Having introduced the reader to his fictional worlds in the first two volumes, and explored all the stresses of their politics and economics in the middle two, Stross has now set all the masses in motion.

As I said in reviewing the first book in the series, this isn’t fantasy, but hard science fiction...but the science in this case is economics. (The cover of this volume quotes Paul Krugman as calling them “economic science fiction worth reading”; and while I doubt that many libertarian readers will be enthusiastic about his particular approach to economics, I’m glad that he’s willing to read and praise a science fiction novel.) Stross’s premise is that a secretive clan of people carry a gene that enables them, when looking at distinctive, complex patterns of knotwork, to move sideways in time. At the outset of the story we learned of one other world, a sort of hybrid between the Viking era and Renaissance absolutism; since then Stross’s hero has learned of two more, and they could be only the start.

Miriam Berg’s reaction to two-way travel between the worlds was to want to modernize the other world as quickly as possible. Much of the static quality of the previous volumes came from her running into massive resistance from the conservative factions among her otherworld relatives. Now she starts learning about the progressive factions, who also have ideas about modernization, though not along exactly the same lines. The two factions go to war. So do the monarchists and revolutionaries of the third parallel world, a kind of steampunk dystopia where the revolutionary impulses of the eighteenth and nineteenth centuries were largely suppressed.

But we also learn that Miriam’s kin have penetrated our world more deeply than was evident before. This gives rise to a passage libertarians will find striking, after a U.S. DEA agent listens to taped evidence of Clan activities:

Did I just hear that? he wondered bleakly. Did I just hear one of the biggest cocaine smugglers in North America ordering his accountant to donate half a million dollars to a zero-tolerance pressure group? Jesus, what is the world coming to?

It made economic sense, if you looked at it from the right angle; it was not in the Clan’s interest for the price of the commodity they shifted to drop—and drop it surely would, if it was legalized or if the pressure to keep up the war on drugs ever slackened. But for Mike Fleming, who’d willingly given the best years of his life to the DEA, it was a deeply unsettling idea; nauseating, even.

Bought and sold: We’re doing the dealers’ work for them, keeping prices high.

This is followed by revelations of just how far into the American political system the Clan have penetrated … revelations that have a disturbing plausibility. And that leads straight on to the climactic headlong leap into the abyss. Where it lands the next novel will show.

In the meantime, Stross has also been showing us a point that E. E. Smith made long ago: what science can achieve, science can duplicate. Researchers funded by the U.S. government prove able not just to understand, but to imitate the Clan’s special talent, using methods of scientific research that the Clan’s world hasn’t yet invented and that most of the Clan don’t understand. So even without the cliffhanger, the next and last novel would inevitably be a story of worlds in collision, with masks coming off and hidden truths revealed. Stross has made me eager, once again, to know if Miriam Berg is going to survive, drag her newfound family into the Enlightenment, and find true love.