The Observer chooses to do something other than observe, abducting a college student. However, when the Fringe team investigates, they discover that there is more than one Observer.. in both time and space.

Just one week after Peter Bishop saved the day and was then wiped from existence, the truce between the two worlds remains intact and the two sides are forced to work together. Lincoln Lee joins the Fringe team as they investigate a shapeshifter case that is very personal to him.

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

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.