I struggle to put a rating on this book. It is absolutely riveting and in parts had me on the edge of my seat, but on the other hand it contains ridiculous action and is a shallow political thriller.
Believe this if you can: a team of people escape being gunned down at point-blank range by crack Delta-force hunters, fall off the edge of the arctic ice shelf on an iceberg which calves away from the glacier and bobs up and down in the water a few times with them sliding around on it, as they are losing consciousness through hypothermia a nuclear submarine pops up and saves them; later they find themselves on a boat above an underwater volcano which has a leg blow off by a pursuing helicopter which lands, takes off while the boat is at an angle and crashes into the superstructure (the boat sits on top of stilts each resting on pontoons), then one gets into a micro-submarine which falls thirty feet onto the water and starts sinking, another dives in after it (with machine-gun bullets whizzing past him, of course) and by pumping water into the cabin manages to blow a window out designed to withstand the weight of seven kilometres of water by air pressure, then when they manage to swim back to the surface a coastguard helicopter comes from nowhere and saves them from a forming whirlpool because the volcano is erupting due to the armaments on the Delta-force helicopter going off at the bottom of the ocean. Five minutes later, the protagonists are standing on a political platform in the middle of Washington D.C.
All this is against a background where people who work for the governement machine have arranged to have a faked meteorite with fossils in it inserted under the polar ice sheet, to be `discovered' by NASA satellites.
It's all just too far out; beyond believability. It is made all the worse by the fact that the characters are shallow stereotypes of US government officials. Finally, in the later stages of the book a third-person narrative appears from nowhere to explain to the reader what is going on. This really intrudes on Brown's straight story telling ability.
And yet, Dan Brown being the clever person that he is, has produced a piece of pure entertainment that really does bring you to the edge of your seat.
On balance, the good and the bad cancel each other out to leave a book just slightly better than most.