It's 1721, the great South Sea Bubble has collapsed**, and a mapmaker, heavily in debt, is persuaded by his debtor that he must travel to Holland and deliver a package. Turns out it contains a green book listing all those government officials who had been bribed to help investors make money from the bubble.
The Goddard books I have read all have some sort of multi-continent chase in them and this one is a whopper. It takes place in England, Holland, Switzerland, Germany and Italy as several groups pursue the rogues who stole the "green" book, which itself had been purloined. Shades of Louise de la Valliere and deception abounds on all sides with poor Spandrel caught in the middle. The Captain was my favorite character.
My only gripe with the book is that I had no sense of place. Here was a marvelous opportunity to present the results of research into traveling conditions, housing, how people lived, etc., in the early eighteenth century. Instead the focus seems solely on the characters and the chase. This may also be one of those books in which the audiobook narrator enhances the reading. Very well read.
**The story of the South Seas bubble is fascinating and well-recounted in this wikipedia article http://en.wikipedia.org/wiki/South_Sea_Company. How little times have changed.