Benjamin Franklin Gates and Abigail Chase re-team with Riley Poole and, 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.

Johnny Kovak joins the Teamsters trade-union in a local chapter in the 1930s and works his way up in the organization. As he climbs higher and higher his methods become more ruthless and finally senator Madison starts a campaign to find the truth about the alleged connections with the Mob.