Preposterous is the word for this one. No other word for it. The sequel to the original 2004 hit is roughly as insultingly stupid, mind-numbingly dull, and embarassingly generic as its predecessor, with almost as much to groan about. If you recall “National Treasure” (2004), that was the one where, let’s see if memory serves, the “hero” had to squirt lemon juice on the back of the Declaration of Independence in order to uncover an invisible coded message; this is scarcely less insane. The film opens “5 days after the end of the Civil War” in Washington, D.C. with John Wilkes Booth, the man who assassinated Lincoln, coming to Thomas Gates (Joel Gretsch), our hero’s great-grandfather, to decode a hidden message written in his diary. This hidden message will involve an extinct Native American language and a secret book passed down between U.S. Presidents that reveals the skinny on, let’s see here, the Kennedy Assassination, the 18-1/2 minute gap on the Watergate tapes, the truth behind the moon landings and, oh yeah, the real truth behind what goes on at Area 51. This code could be the key to opening a pandora’s box of a conspiracy theorist’s wet dreams. Do you really wanna know what that entails? Neither do I. The film picks up with history geek and treasure hunter extraordinaire Benjamin Franklin Gates (Nicolas Cage), still famous after the last film’s adventure, and involves the sudden public revelation of his great-grandfather’s involvement in a conspiracy to kill Lincoln – who, we learn, is Benjamin’s “favorite President.” Benjamin and his father Patrick Henry Gates (Jon Voight) must then contend with a nefarious fellow treasure hunter (Ed Harris), kidnap the current President (Bruce Greenwood) in order to get a key lucky bit of information, and employ the unique skills of Benjamin’s girlfriend Abigail (Diane Kruger); the goofy tech nerd and author of the book about their previous adventure, Riley (Justin Bartha); and Benjamin’s university professor mother (Helen Mirren). Also attempting to cover for Benjamin is his FBI agent pal from the first film (Harvey Keitel). With a cast like this, you’d almost be willing to forgive any goofiness the filmmakers can throw at you. Almost. Indeed, there is a scene early in the film where Cage, Voight, Harris and Albert Hall of “Apocalypse Now” fame are standing around discussing the beginnings of the plot, and I just rolled my eyes and felt myself cringing at the sight of such great actors on such a fool’s errand. Another scene at Buckingham Palace is particularly painful, with Cage in an over-the-top rant designed to distract the guards long enough so he and his girlfriend can get out without being detained, or something. Cage seems to be having fun here, I guess, but I pity him. I really, truly do. Occasionally, the film sparks to life thanks to Helen Mirren’s saucy portrayal of Cage’s mother, and (despite its preposterousness) I also kinda liked the scene between Cage and Bruce Greenwood; you’ll know the one to which I refer. The film has again been directed by Jon Turteltaub (“Cool Runnings,” “3 Ninjas”) and written by, among others, the Wibberlys and Ted Elliott & Terry Rossio (the “Pirates of the Caribbean” trilogy and “Shrek”); they need to find a real day job. The film has unconvincing if fairly servicable special effects and no brain to match. This film is like Indiana Jones for people whose suspension of disbelief has snapped. You would have to be at least half as insane as these characters to even roll with this, let alone enjoy it. I hope you aren’t.