Now, another treasure hunter named Mitch Wilkinson (Ed Harris) has found what is a missing page of the diary of John Wilkes Booth, which contains clues to the location of a lost city of gold, Ben must compete against Mitch to find the lost city, he goes to France and Great Britain to find other clues and even peak inside the President's secret book to put the pieces of the puzzle together, his parents and his friends also help...

Five days after the end of the Civil War, John Wilkes Booth and Michael O'Laughlen, both members of the KGC, approach Thomas Gates to decode a message copied into Booth's diary. Thomas recognizes the message as a Playfair cipher, and translates it while Booth departs for Ford's Theatre to assassinate President Abraham Lincoln.