Charles Stross is a true genre bender. Just when you think you've got him pegged he goes off in a different direction. Often several ways at once. Stross is one of those authors who has a good idea and promptly writes a book about it. And if it works out, he writes another book and makes a series of it. The Merchant Princes explores the idea of inter-dimensional travel, from, of all things, a business perspective.
In the first volume, The Family Trade, freelance journalist Miriam Beckstein discovers that she isn't Miriam Beckstein, but Helge Thorvold-Hjorth, a member of a clan in another dimension that has discovered how to travel to our own, and have set up a drug dealing business in order to buy goodies for their otherwise primitive, barely post-feudal, lifestyle. Think medieval mafia and you will have the big picture. In between various attempts on her life Miriam realizes that the Thorvold-Hjorth business model has reached its limits and she sets off, credit card in hand to make money where no journalist has gone before. Hence this novel, The Hidden Family.
Miriam, in the process of trying to discover who is plotting against her, discovers that there is more than one plot afoot. Somebody else besides the Clan can trip the dimensions fantastic and this new group has discovered an entirely new world of their own, something of a combination of an early 19th Century lifestyle with a good deal of modern science mixed in. Call it techno-Gothic. With three worlds before her, Miriam quickly realizes the opportunities for profit and sets about making a large profit while dodging assassins and plots to wrest her position and power away from her.
This is a great story, but it has some severe believability problems. The most glaring of this is how easy it is for Miriam to set up as an entrepreneur in a world that frowns on women doing much more than child-bearing and tatting. Especially when her stock in trade are things like advanced automobile breaks. Going in the other direction her plan is to track down artworks that were lost in this world, but still exist in the other. It seems to me that setting up in business as a rediscoverer of lost masterpieces is bound to attract a lot of unwelcome attention.
However, if you can manage the willing suspension of disbelief, this is an interesting story that is completely different from run-of-the-mill dimension hopping. Miriam is tough and determined to succeed, and if she doesn't get caught, she is destined to be a billionaire. Now how often do you get to read a series about a billionaire journalist?