This is a sequel to Hartner's previous I, Walter, following the adventures of Walter's second son, James, kidnapped at age eleven by Walter's evil brother Gerald. It's best to think of these books as alternate history, and not worry too much about the details, as the Crofters, father and son, invent first modern international trade, and now, in this book, paper currency and the modern banking system.
That snarky comment made, I have to say that this book, like the first, is solid YA adventure, with lots of action, and with courage, intelligence, and honor prevailing over greed, cowardice, and cruelty. James, Rosalind, and those who help them, and whom they help, are likable people, and James and Rosalind, in particular, don't do foolish things because the plot requires it. They take risks, but with their eyes open and with a solid plan.
Another important note: This is James' story, but Rosalind, Luisa, Ines, and Mary are strong, intelligent characters, too. Rosalind and Mary, in particular, are perhaps a little more successful and independent than is entirely believable in the 17th century, but the target audience for I, James won't mind. Girls and boys both get characters they can identify with, and an exciting and (age appropriately) colorful adventure to enjoy.
I received a free electronic galley of this book from the author.