There's really no secret..."National Treasure: Book of Secrets," the follow-up to the unexpectedly successful "National Treasure" PG-action flick starring Nicolas cage isn't anywhere near a national treasure.

While "National Treasure: Book of Secrets" is, arguably, a visually arresting and lighthearted action flick, it is so completely devoid of anything resembling an original idea, thought, concept or image that moviegoers who demand such things as originality, a decent story or a semblance of intelligence are likely to leave theatres scratching their heads in bewilderment.

Cage is back as Benjamin Franklin Gates, along with his father, Patrick Henry Gates (Jon Voight). Throw in largely the same supporting crew and you have a film that takes the formula that made "National Treasure" a box-office smash and simply repeats it for "Book of Secrets."

In case you're one of the three Americans who managed to avoid the film's trailers, "National Treasure: Book of Secrets" puts Gates back into a historical mystery. This time, Gates is defending the honor of his family after it is revealed, by a dastardly sort, that Gates's Civil War-era relative was part of the conspiracy leading to the assassination of Abraham Lincoln.

This 200+ year old secret leads Gates and his stormtroopers on a 'round the world adventure before plopping us down smack down on Mt. Rushmore, which is really a cover for a City of Lost Gold.

There's a kidnapping of the president so that Gates can get his hands on the long-rumored "Book of Secrets," which supposedly only the president can view (which begs the question of "Who writes the secret and how can they really be secrets if people know about them?").

One gets the sense throughout the film that everyone who signed on for this sequel is acutely aware that they're smack dab in the midst of a de-energized, cloned version of the film's former self. What worked in the original film, and on a purely entertainment level quite a bit did, simply doesn't work here and director Jon Turteltaub never takes the film in any new directions.

"Book of Secrets" is certainly gifted with quite the cast, including not only Cage and Voight, but Helen Mirren, Justin Bartha, Harvey Keitel, Diane Kruger, Ed Harris and Bruce Greenwood. Unfortunately, their characters are generally stock characters and none of the actors are really called upon to do anything resembling acting.

The film's production design is certainly impressive, in that sort of "Why the heck was this really necessary?" sort of way, and the script from The Wibberley's almost seems a paint-by-numbers version of the original "National Treasure."

Despite its rather significant flaws, there remains a general "guilty pleasure" aspect to "National Treasure" that makes it semi-watchable and likely appealing for those who enjoyed the original and/or whom embrace a more family-friendly action film.

While "National Treasure: Book of Secrets" isn't likely to recreate the original's status as a box-office smash nor will it garner any attention during award season, it may very well capture enough of the original's lighthearted irreverence to give it a decent life at the box-office and to make it an entertaining choice for families seeking a decent flick for varying age levels.