Young Benjamin is loitering about in the attic, on a stormy night in 1974, he is about to open an ornate wooden box, when his grandfather John Adam Gates (Christopher Plummer) chances upon him; the old man then narrates to him the story behind the scrap of paper in the wooden box. The year was 1832, the only surviving signatory of the Declaration of Independence, Charles Carroll is anxious to speak to the then 7th President – Andrew Jackson - before he dies. However, the President is not at the White House that night, and Carroll has to share the secret with a stable boy -Thomas Gates, young Benjamin’s ancestor.
Thomas is apprised of a great treasure collected throughout history from different parts of the world, before it was discovered by the Knights Templar - who ‘spaced it out’ all over Europe and America, so that it did not fall into any one man’s hands. The Freemasons, an offshoot of the Templars, with big names like George Washington and Benjamin Franklin had helped the Knights conceal this treasure from the British. They devised covert codes, maps and clues, which only they knew; as time went by, all the clues save one were lost - that last trace was left with Charles Carroll, and it read ‘The secret lies with Charlotte.’ In keeping with the nature of clues - it was so cryptic, Carroll had no idea what it meant!
When Ben asks his father Patrick Henry Gates (Jon Voight) about the treasure and the Knights Templar, he expresses skepticism, and asks the child’s grandfather to leave, but not before Ben asks the old man whether he is a knight. Instead of answering the child, he asks him whether he would like to be knighted, and why would a kid refuse such an offer? John knights Ben, charging him with the duty of finding the treasure.
We meet Benjamin, with his trusty aides - in the inhospitable Arctic, in search for a sunken ship called the ‘Charlotte’. They sift through the wreck, finding only kegs of gunpowder, till the team comes across the corpse, which they think is most likely the Captain’s; what makes it noteworthy is that it sits guarding a barrel, in macabre-after-life allegiance. When the barrel is opened, it cases a meerschaum pipe, in ivory-at the bottom of which is inscribed a riddle:
‘The legend writ, the stain affected. The key in Silence undetected. Fifty-five in iron pen, Mr. Matlack can't offend.’
Apparently, fifty five men had sworn to carry out a task, Matlack was Timothy Matlack, the scribe at the Continental Congress, the men had signed the Declaration of Independence that he had penned. When one of the team - Ian Howe, wants to have a closer look at the document, Ben refuses, reluctant to get close to an artifact of such import; this angers Ian, who declares he can steal the Declaration and find the treasure using the clues in it. Ian steals the pipe and document, escaping, but not before he sets fire to the ship, trapping Ben and Riley (Ben’s friend) in it - the two however, unbeknownst to Ian, escape unscathed.
Back in the US, the duo try and convince the FBI, DHS and lastly Dr. Abigail Chase (Diane Krueger), an expert on historical documents, that the Declaration of Independence could be stolen - no one believes them. Ben tries to win the latter over by sending her the missing election pin of General Washington, as a token.
As Ben and Riley discuss things over, they come to the conclusion that in order for it to be safe - the Declaration must be stolen before it falls into Ian’s hands. This they plan to do at a gala event to be hosted at the National Archives sometime later in the week.
In the guise of a worker at the gallery, Ben makes his way in, he later changes into a tuxedo, offers champagne to Abigail, and uses her thumb print to open the ‘Preservation Room’ using the password ‘Valley Forge’ to get in. He now stands before the Declaration of Independence, but just as he is about to open the case, Riley’s video feed is interrupted - by none other than Ian. With no way out, Ben grabs the case with the Declaration, only to bang into Ian on his way out - dodging bullets, he makes for the elevators, freeing it from its case. Meanwhile Abigail’s suspicions are raised when she does not see the pseudonym Paul Brown (used by Ben when he met her first) on the guest list - cornered; Ben makes a dash for it, whilst Abigail is accosted by Ian and his goons, who think she has the coveted document. Ben saves her, while Ian escapes with a document - a hysterical Abigail is told that the original is still with Ben and she needn’t worry.
The only safe haven for the three now is Ben’s father - Patrick’s house. Here they decipher the inscription behind the Declaration, which further links them to letters written by Benjamin Franklin.
A few more wild chases later, and a clever ruse to get Ben away from the FBI planned by none other than Ian, the duo meet and go down to a tunnel in search of the last clue - only to reach a dead end, that almost costs Ben his life, but he is saved by Patrick who intentionally misleads Ian with a false clue. When Ben is ready to turn over the Declaration, the Agent reveals he too is a Freemason, and promises the safe delivery of the document to the National Archives and arrest Of Ian. Considerably richer and financially secure Ben and Riley call it a day, with Riley still grumpy about the money they could’ve earned.
The movie has been called all sorts of things, ‘silly’ being one of them, but an enjoyable ride for kids and adults alike, despite holding only a 44% rating with Rotten Tomatoes.