White House watchers who accuse the administration of chronic secrecy might find some consolation in Disney's "National Treasure" sequel. As luck would have it, there is a presidential book squirreled away somewhere in Washington that contains all of our national secrets, including the missing minutes of the Watergate tapes. And where all is concealed, all may someday be revealed.

Like its 2004 predecessor, any few minutes of "National Treasure: Book of Secrets" creates the illusion of containing the whole of America's accumulated mysteries. The secret of the Jerry Bruckheimer franchise can be found in "Ragtime" and its lesser-known fiction forerunners: take a historical moment of some note, distill the most known details, then mix some fictional characters into the foreground. And darn it if we don't think we're actually learning something.

Where "National Treasure" conflated the American Revolution with a "da Vinci Code"-ish hash of Masonic lore, the follow-up rewrites the assassination of Lincoln. Or perhaps you didn't know that John Wilkes Booth and his henchmen had a hidden agenda, which involved finding the treasures of a lost pre-Colombian city?

With the help of techno-savvy buddy Riley Poole (Justin Bartha) and ex-girlfriend Abigail Chase (Diane Kruger), Ben resorts to madcap desperate measures that entail the disruption of Buckingham Palace and the Library of Congress. He is also not above kidnapping the president, who turns out to be a good sport about the whole thing once he realizes what's at the bottom of it.

Chief among the other good sports on hand are last year's Oscar winner Helen Mirren, letting her hair down as Ben's know-it-all linguist mom, and Ed Harris, in menacing mode as a treasure seeker with revisionist-history ends of his own. There is also a credible but uncredited cameo by the four stone faces of Mount Rushmore.

It's all pretty inane if you stop to think about it, but director Joe Turteltaub works tirelessly to make sure we don't. I respected "National Treasure: Book of Secrets" for its energetic, good-humored demeanor and lack of pretension.