Who are you? After sacrificing himself to save both worlds, Peter mysteriously returns to ours. But he has been forgotten, by Olivia, by Walter, by everyone. It's as if he never existed. At the same time, shapeshifters controlled by an unknown master begin an onslaught of destruction, and now the two former enemy universes must cooperate to defy a common foe. Fringe's thrilling 22-episode fourth season continues the inspired series' synthesis of astounding...

The fifth and final season delivers a climactic conclusion. Picking 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, which will bring together all they have witnessed in preparation for the final battle to protect our world.