The Gates family is a famous family of adventurers. Ben (Nicolas Cage) learned a shocking secret of their family when he was a child: the place where the national wealth was buried when the United States was founded was hidden in the Declaration of Independence. Although his father did not want the Gates family to be entangled in national treasures, Ben still started a treasure hunt with computer expert Reilly (Justin Bartha). Ben's treasure hunt plan soon came to a standstill. At the same time, British tycoon Ian (Sean Bean) also set his sights on the treasure. He sent people to sneak into the National Library of the United States to find the secret of the treasure in the Declaration of Independence and plot against Ben. After learning of Ian's sinister intentions, Dr. Abigail (Diane Kruger) of the library decided to help Ben find the national treasure...