Benjamin Franklin Gates and Dr. Abigail Chase -- who found riches and romance at the end of their first hunt for national treasure -- reteam with their wisecracking partner in crime, Riley Poole, for another romp through U.S. history. Now, armed with a stack of long-lost pages from John Wilkes Booth's diary, Ben must follow a clue left there to prove his ancestor's innocence in the assassination of Abraham Lincoln.