And there are more things different in it than we even suspect.
This Ep was back to 100% of the velocity of Season 1, back when the show we have been watching for the last 3 and a half years was just developing. SO we have the newness of that renewed in this fantastic Ep which has been anticipated greatly.
When it comes down to it, Peter simply cannot trust the people he had learned to trust in S1-3. Walter absolutely will not cooperate with him much less speak to him, so he is forced into a course of action he really does not want to do.
And so in this Ep we learn a few more things that are different than they are in our normal set of Fringe 'Verses. One of those things allows Peter and Agent Lee to cross over to their other side.
The question has always been, who is making these shapeshifters, and who ARE the shapeshifters? Well get ready to have a mind blowing epiphany down that avenue. And in the subject of epiphanies, add in that Peter will find his greatest Ally of all, in a place where he never expected it. Things are WAY Not as they appear, in the Orange Tinted Fringe 'Verse! I am glad that they took the time they did to get to this 'sode, if it were revealed earlier in the season, it would have just wrecked the whole continuity. And so there are two very disturbing things we get to see - IN the Orange Fringe 'Verse. We just have to ask the Bald Guy - Isn't there anything he could be mistaken about? I have no theories or explanations of this ep, I have no musings of what lies ahead. This is Virgin Territory. And it is the Fringe I love. Of course we do not like where Peter is at this point, but the more time I spend Orange the more I like it.