Up till now, I thought Darrell Bock's Breaking the Da Vinci Code was the best book on exposing the errors of Dan Brown's multi-million selling foolishness. This new book is slightly better, primarily because it's more comprehensive.
For one thing, it extensively quotes not only the main characters in Brown's book as they relate their version of "history," it also has quite a few quotes from the author himself from various interviews. These quotes are then examined for accuracy in relation to a wide variety of expert opinion. In every case, the quotes Brown has his characters utter, as well as his own quotes, are shown to be either simply false or the opinions of a tiny minority of authors whose views have been found wanting at the bar of history and scholarship. This book, which is about twice as long as Bock's book (which is limited pretty much to the time before Constantine and the Council of Nicea), also covers a good deal more ground. Topics addressed include Holy Grail myths, the real Templars, the Priory of Sion silliness, and errors in interpreting not only Leonardo's Last Supper but his take on art, the occult, and Christianity in general.
If you think The Da Vinci Code--the foundations of which are a synthesis of Holy Blood, Holy Grail, The Templar Revelation, The Chalice and the Blade, Drawing Down the Moon, and the works of Margaret Starbird and other marginalized and/or discredited books--accurately depicts what really went on in Western history (which no serious person does who has any familiarity with the available materials), then you will not like any of the books debunking Dan Brown's ridiculous book, least of all this one. But if you want to find out what really happened, this gives as complete an accounting as you'll find anywhere.
In sum, this critique is extensive, even exhaustive, and in the end entirely persuasive.