By the way, maybe it was just my imagination, but did Walter look a little younger to you at the end of tonight's episode? Just sayin'. And Astrid looked different, too.
The story was a cool return visit to an episode from Season One, with a souped up DNA turning its carriers into porcupine creatures. Tonight the bad guy behind this is David Robert Jones, which my wife realized is played by the same actor who plays Lane on Mad Men (Jared Harris). Fine acting - two wildly different, excellently played characters.
Otherwise, Olivia is in danger of losing her job at the FBI - she's lost 40-percent of this season's (world with Peter erased after Reiden Lake) memories, and which the 10th Floor (FBI brass) finds an insufficient amount of the Olivia they hired. By the end of the episode, Broyles nobly stands up for her, figuring that Olivia's better than 90% of the agents, so 40% of her is still a good number. Admirable algebra.
But there's something about this, our world, minus Peter after the lake, to which Peter has now returned, which may still need a little explaining. How come Peter's absence has changed so many things in the world, including all kinds of events with which he had nothing to do in the original world, such as, for example, Lincoln Lee being such a major character in this world that developed without Peter?
Wait a minute - maybe Peter did have something to do with Lee's prominence - Lee moved into the void that existed in Fringe in Peter's absence. And the porcupine people - why did they take a different path in the without-Peter-world? Because without Peter, without Peter and Walter as antagonists, Jones became more powerful. The indirect effects of Peter's absence being so great show how important Peter was in that world, in ways we didn't realize.
And so the shook-up kaleidoscope is gradually reassembling ....
... Fringe 4.2: Better and Worse Selves ... Fringe 4.3: Sanity and Son ... Fringe 4.4: Peter's Back, Ectoplasm, and McLuhan ... Fringe 4.5: Double Return ... Fringe 4.6: Time Slips ... Fringe 4.7: The Invisible Man ... Fringe 4.8: The Ramifications of Transformed Alternate Realities ... Fringe 4.9: Elizabeth ... Fringe 4.10: Deceit and Future Vision ... Fringe 4.11: Alternate Astrid ... Fringe 4.12: Double Westfield / Single Olivia ... Fringe 4.13: Tea and Telepathy ... Fringe 4.14: Palimpsest ... Fringe 4.15: I Knew It!