Season five picks up from events depicted in season four's flash-forward episode the seemingly peaceful Observers seized control of our universe in 2015. Now, in 2036, they have become ruthless rulers who stand unopposed. What awaits in the future, however, is the Fringe Team's final stand to protect our world.
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.
The Fringe team revisits the Harvard lab, now under Observer control, to try to find the information they need as the team fights on in their mission to save the world.
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 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 is running out of time to save the world. As Peter, Olivia, Astrid and Walter scramble to tap into a key piece of the puzzle to defeat the Observers, they enlist the aid of Nina Sharp who conjures up a plan.
As time dramatically ticks down, Peter, Olivia and Walter stop at nothing to save the universe from Observer rule. Walter enters the infamous deprivation tank in an attempt to uncover a key piece of information about the mysterious figure, Donald. Meanwhile, Captain Windmark sets out on a revealing mission of his own as long-standing questions are answered.
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.