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.