Access to 'The Book of Secrets', which only the Presidents of America are privy to, is altruistic treasure hunter Ben Gate's latest 'mission impossible' and with it he must find/save the city of lost gold' from those who would do bad. As soon as National Treasure 2 finished I had immediately forgotten what had happened; but it's sub-Indiana Jones doing the Da Vinci Code, big-of-budget, tongue-in-cheek, relentlessly paced popcorn movie-making of the highest (lowest?) order, and that PG certificate makes it perfect family' viewing.