The Fringe team - preserved in amber for 20 years - is now a rebel resistance team fighting for freedom. Peter, reunited with his now adult daughter, Etta, sets out to find out what happened to his wife and Etta's mom - Olivia - as they start their mission to save the world from the Observers.

As the rogue Fringe team continues to fight off the oppressive Observers’ invasion, unforeseen events lead them into a forest where they encounter a strange subculture of people devoted to recording human history.

The Fringe team responds to recent devastating events, and a key member makes a pivotal and shocking move.

The team retrieves another cassette tape from the amber. With Nina Sharp's help, the team recovers 2 cylinders. While Peter works independently to score a minor victory against the Observers, Olivia ascertains Peter's secret.

Olivia encounters a very intuitive and oracle-like person named Simone as she looks to recover a key piece of equipment for Walter. Meanwhile, Peter finds himself in a perilous situation as he observes Windmark.

In attempt to recall a plan to defeat the Observers, Walter takes an LSD trip down memory lane. Meanwhile, Peter and Olivia trace a mysterious signal to the woods, where they come upon a grisly scene.

The Fringe team engages a desperate plan as Olivia embarks on a dangerous and otherworldly journey into the unknown. Then, Peter, Olivia, Walter, Astrid and Broyles face off against the Observers in one final and extraordinary battle for the fate of mankind.