This us the best episode of Fringe so far. Perhaps I should explain my reasoning.
At Massive Dynamic, Walter has a serious concern for Peter. HE SHOULD. Walternate's blueprints matched up with Peter. That triggered Thomas Newton to reunite Peter with his father so he could destroy this side in "Northwest Passage". In "Do Shapeshifters Dream of Electric Sheep?", he is finally dead. He was the worst shape shifter of all. This episode focuses on shape shifting, too, like "A New Day in the Old Town", "Night of Desirable Objects", "Momentum Deferred", "Earthling", "Grey Matters", "The Man from the Other Side", "Northwest Passage" "Olivia", "The Box", "Do Shapeshifters Dream of Electric Sheep?", "6955 kHz", & "Entrada". In this episode, a shape shifter is found dead in a lake. Looks like it's a shape shifter killer. But who is it? Watch Fringe to find out.
So, you see, this is so good this episode. There could be another episode that beats it, but this is the best. So, I guess it's the right time to say "the end".