The key to deciphering this second installment of the bombastic Jerry Bruckheimer-produced adventure through history is: more of the same.  If you enjoyed the first NATIONAL TREASURE film (and I did), then you'll likely enjoy NATIONAL TREASURE: BOOK OF SECRETS sequel too (as I sort of did).   Benjamin Gates (in a even more thinly drawn role for Nicholas Cage to enact the second time) must save his family's honor by disproving a recent revelation that his ancestor may have planned President Lincoln's assassination. When Jeb Wilkinson (Ed Harris) produces a missing page from John Wilkes Booth's diary implicating old Thomas Gates as the plot mastermind, Benjamin must marshal his father (Jon Voight), ex-girlfriend (Diane Kruger) and geeky cohort Riley Poole (Justin Bartha) to unravel yet another string of historically hidden clues to find a lost City of Gold.   If the city exists, ye olde Gates will be proved a patriotic hero of the Union by dying to protect its hidden location by burning clues to find it; but fail to find the treasure city and the Gates' family will forever be remembered as traitors who nearly brought down our republic. Along the way Ben kidnaps the President and recruits his estranged mother (Helen Mirren) to gather vital clues which point the trail to a long-buried legend and truth.

With those bare-bones plot points established — very quickly, I might add — the audience needs not wade through any more setup and gets right to munching their popcorn through the action ahead.   This, indeed, is the raison d'etre of BOOK OF SECRETS: to deliver more chasing, digging, tunneling and rope swinging, burdened down by as little dramatic story and character development as possible (even by Bruckheimer Films' standards).

Ben and Abigail's on again-off again romance makes a more convincing subplot than the Patrick/Emily thread, and Diane Kruger fares better in this outing.  Yet splitting the story's puzzle solving between six primary characters weakens the overall effectiveness and impact of each role, to the film's detriment.  Riley Poole is reduced to an even shallower repository of bumbling and one-liners, yet Justin Bartha's innate charm once again wins audience affection and earns some deserved laughs amid the action.

Like the ancient American balancing-act boobytrap the treasure hunters encounter, BOOK OF SECRETS strives to balance plentiful mindless action with a few weightier moments of family honor and American duty, all dealt at a dizzying pace so neither the characters nor audience can take either pursuit too seriously.   Nor should that be the goal of anyone buying a ticket to this sequel — just buckle up, hang on and dive in for a rollicking ride of expansive vistas and explosive special effects.

In this sequel's case, the ancestral prologue of Thomas Gates decoding a Confederate plan to kill Lincoln and turn the tide of the Civil War makes a neat jumping-off point, but Ed Harris' underwritten Southern heavy fails to live up to this mystery's potential.  A harbinger of little more than plot complication, he implicates the Gates' ancestry for littler other reason that to force another treasure hunt.  Even Harvey Keitel's returning FBI caser Sadusky questions the illogic of this revelation, and it's never a good sign when your own characters question the script they inhabit. Ultimately a dramatically involving threat to fails to emerge, and the desire to urge Ben to clear his family name fizzles in the gloom of another ancient obstacle course.

If you're like me, it's the history in which these treasures and traps are enfolded which make the conspiratorial craziness of this new quest entertaining if only semi-believable. A line of Presidents handing down a collected album answering America's greatest mysteries, and national monuments concealing (if not obliterating) clues to time-lost fortunes is fun exercise for the imaginative wonder. These secrets' audacious impossibility are what make them such delicious nuts to crack by definition, and BOOK OF SECRETS delivers on this count. 

Should audiences hungry for a second treasure chase actually care about logical motivations setting all this sound and fury into motion? Probably not, but that doesn't satisfy the urge that moviegoers encouraged by the first film might desire more nourishing fare than this cinematic buffet of cotton candy.  NATIONAL TREASURE's original ambitions were fueled by enough creative gumption to inspire bigger and better in a sequel, whereas BOOK OF SECRETS successfully but simply delivers nothing more but more.