Three years ago, Jerry Bruckheimer, with his unfailing ability to produce movies that make endless amounts of money without filling any previously unfulfilled need, oversaw National Treasure, a moderately silly, moderately stupid and shockingly enjoyable matinee-style adventure yarn best described as "The Da Vinci Code but with American history."

Bruckheimer being Bruckheimer, it is deeply unsurprising that there is now a sequel, National Treasure: Book of Secrets, and it is a little sillier than the original, and a little stupider, and somehow it still manages to be shockingly enjoyable. It's no Indiana Jones or North by Northwest - both obvious inspirations for the tiny army of scenarists and screenwriters - but in all its unabashed goofiness and cheerful, almost crazed disregard for this thing we call "reality," Book of Secrets is just about the breeziest popcorn flick to come out all year, besting by a considerable margin Bruckheimer's last franchise effort, the leaden and overlong Pirates of the Carribbean: At World's End.

Some ill-defined amount of time after the events of National Treasure, Book of Secrets starts off by pushing RESET buttons all over the place: Ben Franklin Gates (Nicolas Cage) is no longer living with sexy German immigrant/historic documents specialist Abigail Chase (Diane Kruger); Ben's tech-savvy aide Riley (Justin Bartha) has lost all of his money earned in the first film's climax, apparently on the vanity-press run of a well-researched bit of crackpottery purporting to explode governmental conspiracies, and the newly-rehabilitated Gates family name is dragged back into infamy thanks to a mysterious Southern man named Mitch (Ed Harris), who claims to have proof that Ben's ancestor once planned the assassination of Abraham Lincoln.

Since this is the kind of movie that it is - the sequel to "The Da Vinci Code but with American history" - Ben quickly decides that the best way to clear his ancestor's name is to use John Wilkes Booth's diary to find the lost city of gold, Cibola; it's best not to dwell on the hows and whys, but this requires quick jaunts to Paris and London, a brief stint in Virginia to capture the President (Bruce Greenwood), and finally a jog 'round Mount Rushmore. Along the way, Ben and company enlist the help of Ben's dad Patrick (Jon Voight, reprising his role from before), and the brand new conflict-generating figure of Ben's mom, the Mesoamerican language specialist Emily Appleton (Helen Mirren).

Lord knows it's hokum, but it's pretty damned entertaining hokum, and there are a lot of small reasons why this ought to be the case. Primarily, I suppose, it's that the film never really pauses to let you reflect on all of its inconsistencies and lapses in logic. Jon Turteltaub is nobody's idea of a major director, with a severely anonymous body of work to this point from 3 Ninjas to Instinct, but he achieves his extraordinarily modest goal as well as anyone could: keep everything moving as quickly as possible but don't let anything seem rushed. There's some dead spaces early on, and a rather significant portion of the plot doesn't actually advance the plot much at all (the titular Book of Secrets doesn't show up for what seems like a full hour), but nothing really lags much. It's a film that rewards settling back and holding all questions until the end of the ride (questions like: why did the Lakota Sioux write in Mesoamerican glyphs?)

Honest compels me to acknowledge that another key to the film's swift, easy tone is the leading man. I've not spared Nic Cage much sympathy in the past, but he hasn't done much to deserve any, with The Wicker Man and Next looming so recently in his past. When the first National Treasure opened, Cage was only two years away from his exceptional work in Adaptation.; here in 2007, he hasn't been much good at all in ages, and his scripts have been worse. So "the best Nicolas Cage film in years" doesn't mean much, but that's exactly what Book of Secrets is: the first film since its predecessor three years ago in which Cage has been at all interesting to watch. Moreover, it's precisely the Caginess of his performance that works in this film's favor: his default mode is affable and goofy and just close enough to cool that you can see it if you squint, and that's exactly the lead performance that this affable and goofy adventure movie needs.

For all it's looseness, Book of Secrets does feel a bit more consciously put-together than National Treasure, like the filmmakers wanted to make certain that everything from the first go-round was in place again, and this leads to some clunkiness where you can almost see the mechanics of the script grinding together: perhaps most obviously in the decision to open with Ben and Abby split up, a clear bid to recapture the romantic tension of the first film (I am fleetingly reminded of The Jewel of the Nile, which played the same card and did so as poorly as it can ever be done). Then there is the rather winding and arbitrary way that the first act sets up the MacGuffin, or the mostly pointless addition of Ben's mother, although no decision which introduces Helen Mirren to a film's cast can rightfully be called "pointless."

Then again, Book of Secrets has significantly better setpieces than the first film, and like the first film there is no sense that they were deliberately toned down to achieve a PG rating. And as is his wont, Bruckheimer proves himself willfully unafraid to spend massive sums of money, and to put every dollar of it on-screen. When the heroes find the city of gold (yeah, like that's actually a spoiler), it's a miracle of fussy production design, even if it doesn't really make a lick of sense.

All in all, there's nothing in this film quite as bizarrely exciting as the notion that the founding fathers deliberately made the eastern seaboard a giant puzzle box, but that doesn't keep the new film from eking out its own charms. They are, by all means, modest charms. But they are real charms anyway. Don't go in expecting a smart film, don't go in expecting craftsmanship like you get from a Steven Spielberg; just go in expecting a bit of silly fun, and you'll be pretty much fine.