National parks and Native American glyphs............


Plot[edit]On April 15, 1865, five days after the end of the Civil War, John Wilkes Booth and Michael O'Laughlen enter a tavern in Washington DC and approach Thomas Gates to decode a message in Booth's diary. Thomas recognizes the message as using the Playfair cipher and begins to translate it. While he does so, Booth leaves for Ford's Theatre and assassinates President Abraham Lincoln. Thomas solves the puzzle and realizes the men are members of the Knights of the Golden Circle and are Confederate sympathizers. A fight breaks out, and Thomas rips several pages from the diary and throws them in the fireplace. Thomas is shot, and the gunman retrieves only a page fragment.
More than 140 years later, Thomas's great-great grandson Ben Gates delivers a lecture on the story at a Civilian Heroes conference. Black market antiquities dealer, Mitch Wilkinson, shows one of the 18 missing pages of John Wilkes Booth's diary, with Thomas Gates' name written on it, convincing everyone that Thomas was not only a conspirator, but also the grand architect of the Lincoln assassination. Ben sets out to prove the innocence of Thomas.
Using spectral imaging, Ben, his estranged girlfriend Abigail Chase, and friend Riley Poole discover a cipher pointing to Édouard Laboulaye, hidden on the back of the diary page. Ben and Riley travel to Paris, where they find a clue engraved on the torch of the scale model of the Statue of Liberty, referring to the two Resolute desks. One of the desks is used by the President at the Oval Office in Washington, while the other is used by the Queen in Buckingham Palace in London.
Ben and Riley then head to London to infiltrate the Palace and Abigail shows up, unannounced. From the Queen's desk, he obtains an ancient wooden plank. Meanwhile, Wilkinson has broken into Patrick Gates' house and cloned Patrick's cell phone to track Ben's whereabouts. Wilkinson eventually obtains the wooden plank, but not before Ben manages to photograph the symbols carved into the plank.
At Ben's insistence, Patrick reluctantly asks his ex-wife and Ben's mother, Dr. Emily Appleton, for help in translating the symbols. She does so, but points out that some of the glyphs are partial, leading Ben to conclude that another plank must be hidden in the other Resolute desk at the White House.
Ben and Abigail coax Abigail's new love interest, Connor, a curator for the White House, into letting them into the office to see the desk. Ben discovers that the second plank is missing, but he does find a stamp bearing the seal of the "President's Secret Book". Riley tells Ben that the Book of Secrets contains documents collected "by Presidents, for Presidents' eyes only", covering such controversial subjects as the JFK assassination, Watergate, and Area 51.
Ben crashes the President's birthday party at Mount Vernon to convince the President to follow him into a secret tunnel under the House, where he confronts him about the book. The President warns Ben that his actions will be interpreted as an attempt to kidnap the President and Ben is now wanted for committing a federal offense. Ben convinces the President to reveal the location of the book, which is at the Library of Congress.
In the book, Ben finds a picture of the missing plank from the desk and an entry by President Coolidge, who found the plank in 1924, had it destroyed, and commissioned Gutzon Borglum to carve Mount Rushmore to erase the map's landmarks in order to protect the treasure. However, FBI Agent Sadusky tracks Ben to the Library and the three narrowly escape capture.
Ben, Riley, Abigail, and Patrick then head to Mount Rushmore, where they meet Mitch, who has kidnapped Ben's mother, Emily. Mitch helps them find the entrance of a cave, containing the legendary Native American city of gold, Cíbola. Once inside, they encounter several traps and everyone gets separated. Eventually, they find the city of solid gold underneath Mount Rushmore and it begins flooding with water. In order to get out alive, one person has to stay behind to hold open the door to the tunnel. After a struggle and Ben's attempt to sacrifice himself, Mitch ends up staying behind and asking Ben to give him the credit for finding the treasure.
Ben clears his family's name with the discovery and is cleared of all charges when the President, in an attempt to protect Ben, tells everyone that Ben saved his life. Ben also ensures Mitch receives joint credit for the find. At the end, the President mentions the favor he asked of Ben when he gave him the location of the Book, implying that a third movie would be forthcoming.