Thanks to math bloggers Evelyn Lamb and Kate Owens for bringing this book to my attention. Somehow it eluded my detection for these seven years! But, I do have a paperback copy on my dresser now and I will hopefully get a chance to read it sometime soon.

Update: I've now read Lost Empire and I completely agree with Evelyn's assessment. Indeed, the mystery in this adventure novel hinges on the writings of a 19th century mathematician named Blaylock who made a discovery about the origins of the Aztec civilization while on assignment as an American agent in Tanzania just after the Civil War. (If that sounds unbelievable to you, then this book is not for you because there are tons of occurrences here that seem even less likely than that. Each of the heroes' daring escapes struck me as impossible, and the villains' motivations also were quite hard to swallow.)

As she says, it is anachronistic for them to have described him as being a topologist in the 19th century. The only math he uses in encoding his secret message is a Golden spiral associated with the Fibonacci sequence, and contrary to what the book says repeatedly, that is not topology. (Topology is the study of geometry without any sort of measurement. Specific distances or angles don't have a role in topology, but those things are precisely what make a Golden spiral.) And, again confirming Evelyn Lamb's criticism, on page 381 the CalTech professor that they consult for help with the spirals says of Blaylock:

(This misconception surprises me. Math is generally criticized for being too abstract!)

In addition, although the character of Blaylock does break some of the mathematician stereotypes (e.g. he is strong and has fighting skills), the book also repeatedly suggests that he suffered from a mental disorder:

As you know, I get very tired of the "crazy mathematician" trope. It would not have changed this story much at all if they had just let poor Blaylock remain sane until his death, but Cussler and Blackwood chose to follow the rule (perhaps more like a "guideline") that all mathematician characters in fiction must be portrayed as certifiably insane.

On a separate note, one thing I found odd about this novel was the degree of detail. From a discussion of the ingredients in the food they order in a restaurant to the precise method that they used for raising an artifact from the sea floor, this book went into far greater detail than I am used to seeing in fiction. I suppose some people may like that. Furthermore, each of the authors is an expert of sorts. (Cussler is known for his underwater archeological work including his claim to have discovered the wreck of the Hunley submarine here in Charleston and Blackwood has a military background.) So, I suppose they want to show off their knowledge. Unfortunately, their knowledge of math (and physics...there is a clinker about waves also) was underwhelming.