Watch Fringe season 4 episode 19 online replay which episode title is "Letters of Transit" which aired on FOX Friday, April 20, 2012. The said episode shows a far future involving war between the Observers and the Fringe division which will surely make change to what they have believed and lived in. The said story of the episode jumps in 2036 and it shows how the Observers controlled the future with their force while the Fringe division is working underground and hunted. See the preview clip of the episode below.
I am wondering if who's Walter is inside the isolation where the Observers imprisoned him. Well, I should watch Fringe season 4 episode 19 tonight and see if what it is really all about. You can view the video links submitted by tons of users at Telepisodes.li containing the said Fringe episode.