The team must battle the French, Indians and Mother Nature after Flynn sabotages the Lifeboat and traps them back in Western Pennsylvania circa 1754.

With one of our heroes' lives on the line, the team chases Flynn to 1954 through the paranoid corridors of Joe McCarthy's Washington D.C., en route to a secret, once-a-generation meeting of Rittenhouse leaders. While there, Lucy must wager the ultimate sacrifice to save history as we know it.

After barely escaping an explosion at Mason Industries, Wyatt and Rufus chase the Mothership back to a French battlefront during World War 1 to rescue Lucy from Rittenhouse. There, they discover that Lucy has recruited Marie Curie, the famous French scientist and the only person ever to win two Nobel Prizes, to help save the life of a wounded American soldier, only to learn that the soldier is Lucy’s own great-grandfather who Rittenhouse is bringing to the present to be their leader.

The Time Team travels back to 1981 Washington D.C. on the day President Reagan was shot, only to discover that the Sleeper’s target isn’t the President – but a young rookie police officer – none other than Agent Christopher, who brought the time team together and kept the Lifeboat from getting into Rittenhouse’s hands. The Time Team must save Agent Christopher’s life and prevent her from making a mistake that set her on a different path that would forever change her own future, the future of the team -- and the future of the world.

Christmas arrives in the Bunker, and the Time Team is inspired by a visit from their future selves to find a way to try to save Rufus. But when the Mothership jumps to 1848 California, they’re forced to put those plans on hold and chase Rittenhouse back to the Gold Rush, where they encounter one of the era’s most dangerous villains. Then chasing the Mothership to Korea in the winter of 1950, the team helps a stranded, pregnant refugee attempt to escape a tragic fate.