The trio races to catch Flynn in 1972 before he can steal the mysterious missing minutes of the Watergate tape, but personal secrets threaten to tear the team apart.

Wyatt convinces Rufus to steal the Lifeboat for an unauthorized mission to prevent Wyatt's wife's killer from ever being born. Lucy must cover for them in the present, as Agent Christopher discovers the ship is missing and Anthony Bruhl makes an alarming confession.

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.

When Rufus and Jiya add a fourth seat to the Lifeboat, for the first time ever, Connor Mason joins the team as they travel back to the dusty backroads and smoky juke joints of the Depression-era South to rescue the life and legacy of Robert Johnson – King of the Delta Blues, Godfather of Rock n’ Roll and a man who, legend has it, bought his musical genius from the Devil for the price of his soul. Meanwhile, Agent Christopher keeps Wyatt in the present to execute a dangerous raid on Rittenhouse headquarters.

When the Mothership jumps to South Carolina in 1863, the Time Team partners up with a courageous Union spy and military leader, Harriet Tubman - AKA "The General" - to thwart Rittenhouse's plan to alter the outcome of the Civil War. Back in the present, Rittenhouse hits the team where it hurts the most. Then, Jiya makes a daring escape from Rittenhouse that strands her in San Francisco's Chinatown in 1888 with no way home.