Complete story — includes the ending
In the year 2036, Walter notes that he and the Observer September created a plan to free humankind from the Observers' rule, but September fragmented Walter's memory to protect the information. Walter had Olivia retrieve a Thought-Unifier, a device to help restore these memories, but she disappeared. In the present, with the help of Peter, Astrid, and Etta, he frees Olivia from amber. While the others escape, Walter is captured by the Observers. Their Captain Windmark interrogates him for the plan, damaging Walter's mind by using a violent probing technique. Etta uses her Fringe credentials to break into the facility where Walter is held and free him. Afterwards, Windmark connects her to images of a young girl from Walter's mind. The Unifier activates to Walter's touch, but it does not find any memories. Etta suspects that the memories were destroyed, and the plan is lost for good.
Sources and content license
Source and revision history · Adapted from Wikipedia contributors, Fringe season 5. HTML formatting and reference markers removed. · Content license