When I bought this book, I figured it was just going to be another ridiculous yarn about the Templars. I was right, but, unlike several others in this genre I've read, this one was actually entertaining!
The plot revolves around a former US special ops agent, Cotton Malone, who finds himself saving his former boss from mysterious assassins as she tries to discover who sent her her dead husband's research notebook. The notebook supposedly holds the key to finding the missing Templar treasure, called The Great Devise. Malone gathers a group of people who can solve the mystery, including the ousted seneschal of the modern Templars, and tries to stay one step ahead of the new Templar master, who will kill to get The Great Devise.
Even though the plot is fairly common in the academic thriller genre, Steve Barry, the author, takes a slightly different tact in talking about the long-lost Templar treasure. Instead of going mainstream and saying it has to do with the bloodline of Jesus Christ & Mary Magdalene, Barry suggests that whatever the Great Devise is, it has to do with proving, or disproving, the resurection of Christ.
Barry tells a good story, and I find the book hard to put down once I start. I've read a couple other books by Barry, but so far, this is my favorite. If you liked The Da Vinci Code, I suggest checking out The Templar Legacy. It's similar, but different enough to provide a few more hours of entertainment.