After a criminal steals an advanced time-travel ship and goes into the past, an unlikely team including a pilot, a soldier, and an historian is assembled in an attempt to stop him from altering history. But when Lucy Preston and the others arrive at the Hindenburg disaster in 1937 they learn that Garcia Flynn's agenda isn't what they thought.
Lucy, Wyatt, and Rufus chase Garcia Flynn to the night of President Lincoln's assassination in 1865, where they must stop the terrorist from executing a larger plot involving murders that will alter the shape of American history.
The team travels to Las Vegas in 1962 with the suspicion that Flynn may be targeting Jack Kennedy -- only to find that he's after one of the era's most influential women. Rufus encounters the scientist abducted from the time facility and learns that his former mentor may be a part of the conspiracy.
Lucy, Wyatt, and Rufus chase Flynn to Nazi Germany, where they suspect he is planning to give an atomic weapon to the enemy. While they team up with a British spy, Lucy suffers from self-doubt.
After Wyatt learns that he is being replaced he joins the team on one last mission to the last stand at the Alamo in 1836, where they find themselves surrounded in the famous fort -- and where Flynn has made a pact with General Santa Anna.
Rufus continues to struggle with divided loyalties when the team steps into the Watergate crisis of the 1970s, searching for the legendary deleted portion of the Nixon Tapes. With Wyatt held captive by Flynn, Lucy and Rufus' investigation leads them to a woman with ties to the mysterious Rittenhouse.
After Flynn's people sabotage their time ship the team find themselves trapped in the year 1754, attempting to elude French soldiers in the woods of Pennsylvania while working out how to get home -- and how to trust one another again.
Lucy, Wyatt, and Rufus sneak into NASA during the fateful hours of the moon landing in 1969, and must enlist the help of one of history's unsung heroes to rescue the Apollo 11 crew. Elsewhere, Flynn makes contact with a young mother who works at Mission Control.
Lucy and Wyatt find themselves on the run with the infamous bank robbers and ill-fated lovers Bonnie Parker and Clyde Barrow, trying to beat Flynn to a mysterious amulet with a connection to Rittenhouse.
The team travels to the American Revolution and meet General George Washington, who orders them to capture the trader Benedict Arnold from the British -- along with help from Garcia Flynn, who offers them a dubious pact. Agent Christopher asks Lucy for a deeply personal favor, and Mason comes to Rufus with an ultimatum.
Rufus and Wyatt head to the 1893 Chicago World's Fair in search of Lucy, who has been captured by Flynn as part of a desperate new plan to decimate Rittenhouse by targeting its high-profile members throughout history -- only to fall into a sinister trap.
After Flynn rescues Jesse James from history's fate and enlists his help, Wyatt leads the team on a mission to kill the legendary outlaw in the 1880s frontier -- where they join forces with the lawman who will be the basis of the Lone Ranger legend.
Wyatt convinces Rufus to take him back to 1983 to prevent the parents of his wife's killer from ever meeting, but they soon find their mission slipping away as a storm traps them inside a hotel bar. Meanwhile Anthony asks for a meeting with Lucy, armed with a drastic plan to halt Rittenhouse's terrifying plans for the time ship.
Having lost Wyatt, Rufus and Lucy travel to 1927 Paris -- where Flynn has show down and captured Charles Lindbergh near the end of his transatlantic flight. Rittenhouse moves in on the Mason Industries facility, and Agent Christopher finds herself on the outside looking in.
Lucy, Wyatt, and Rufus look for help from famed lawman Elliot Ness after Flynn allies himself with the notorious gangster Al Capone in 1931 Chicago, but must take drastic action to bring Capone to justice after history is altered.
The team narrowly escapes the enemy to travel to 1954, where Lucy and Wyatt must locate a secret meeting of Rittenhouse leaders before Flynn can take them all out. Rufus grows concerned when Gia's first trip back in time has unforeseen consequences.
