Lucy, Wyatt, and Rufus chase terrorist Garcia Flynn to the night of Lincoln's assassination, where they're horrified to learn that Flynn's linked up with history's most notorious assassin, John Wilkes Booth. Putting aside a tragedy of her own, Lucy speculates that Flynn intends to send the fragile nation into chaos by making a bad thing worse, and a debate rages among the team: should they alter history if it means changing it for the better?