In the year 2036, Peter, Astrid, Walter, and Peter's daughter Etta set out to find Olivia, who holds the secret to uncovering the master plan that will allow the rebel fighters to defeat the occupying Observer force. 

The fight for freedom intensifies when the Fringe team revisits Walter's Harvard lab, which is now under the control of the Observers. 

To find a mineral necessary for their plans, the team travels into the wilds of Pennsylvania and finds an encampment made up of people who are recording human history since the invasion. 

After tracking a lead to a hostile and heavily guarded location, the team are reunited with Phillip Broyles. However, can he be trusted? 

A recent devastating event leads to a change in strategy before a key member of the team makes a pivotal, not to mention shocking, move. 

A team member turns their hand to a new role, and Walter uncovers a key piece needed to defeat the Observers. 

In a game-changing episode, a member of the team decides to orchestrate a `Fringe' event of their own. 

Olivia comes across a woman who is like an oracle, as she works to locate an important piece of equipment for Walter; Peter finds himself in danger as he watches Windmark. 

Walter tries to remember a plan to defeat the observers; while following a signal to the woods, Peter and Olivia come across a gruesome scene. 

Time is running out and, scrambling to tap into the key piece of the puzzle to defeat the Observers once and for all. the team enlist Nina's help. 

While Walter enters the deprivation tank to find out more about the mysterious Donald, Captain Windmark sets out on a revealing mission of his own. 

As the dizzyingly inventive drama reaches the end of its fifth and final season, will Olivia, Peter and Walter triumph against the Observers? 

Peter, Olivia, Walter, Astrid and Broyles face off against the Observers in a battle for the fate of mankind.