Great episode tonight. I'm really loving this season. Everything from Walter revealing he has memories of the other timeline to September/Donald's return to more information on the Observers to the cliffhanger was just compelling stuff. I'm not surprised that Walter will be making the ulimate sacrifice for the success of the plan. Now that he has overcome the impulses of his dark former self with the help of the Observer boy, Walt can take the necessary steps to complete his redemption. No doubt the moment when Walt reveals what he has to do to Olivia, Peter, and Astrid will be heartbreaking.
I'm happy as hell that Alt-Fringe will make a return in the series finale. It wouldn't have been right for the show to end without it. I look forward to how much things have changed with Lincoln and Alt-Olivia over there.