The Mad Science of Fringe: Who's Season Two's Main Villain?

Last night, Fringe followed up its shaky music-themed episode with more fallout from Peter's revelation that he's from the other side. And we finally find out why the hybrid soldiers brought back Thomas Newton, why he was looking for a path to the other side, and who he answers to. Read on for those answers and for an analysis of the most pivotal scientific -- and character-based -- threads in "Northwest Passage."

Scenario: The Walternate is behind everything!

Plausibility: 10 of 10. People have been calling this one since Walter nicknamed his alt-world ego in the episode "Peter," but the slight predictability isn't a turnoff -- it's a great payoff for those that watched the Walter-Peter thread develop since the end of season one. Seriously, what answer could have been more satisfying? In the end of the episode, Peter comes face-to-face with both Newton and the Walternate before the smash to black. It's hard to imagine, considering the lengths Walter's gone through to win Peter's affection (and life) that the Walternate wouldn't take equally drastic measures. And if Walternate proves as damaged as Walter over the loss of his son, next week's looming showdown is sure to be at once tragic and mirthful... through probably more tragic.

Scenario: The ambiguity of Peter's origins seems to have left his purpose in doubt. He doesn't want to talk to Walter or Olivia -- he just drives aimlessly until he ends up in Washington State, where he helps a local sheriff with a murder case.

Plausibility: 7 of 10. Peter's upset. I get that. And to some extent, his packing up and taking a road trip makes sense. He did, after all, spend the years before Fringe racking up debt and making friends in dark places. It's his disregard for poor Walter that shocks me, but I suppose he'll come around next week after he's abducted by Newton and Walternate.

Scenario: To help the sheriff solve those murders (in which two bodies are found missing chunks of brain and skull) Peter examines adrenaline in the muscles and finds out how much time passed between the initial attack and the murder. The killer, the sheriff reasons, probably traveled at about 45 miles per hour from the attack point. Compare that to the time it took for the second spike of adrenaline and we can assume a location.

Plausibility: 8 of 10. It's hardly the most important point of the episode, but it's nice at least to be able to cover the scientific bases with some reasonably devised and hugely imaginative solutions. Peter, it's like you went to med school or something (or at least forged a degree)!

How'd you feel about the revelation of the Walternate? And is Peter being unreasonable? Or perhaps too forgiving?