Let's start with the usual praise about the acting : Joshua Jackson was great, definitely more Observer-like than last week, but maskerading it behind fake smiles reminding us this guy used to be a con man. The way he looked at Walter in the lab at the beginning, like he doesn't understand humans any more, sent chills down my bones ! John Noble was also awesome in his scenes with Blair Brown : both were good, actually ( when Nina meets Olivia, I almost cried ! ), switching effortlessly between helpless Walter and Walternate-level of coldness ( "He never loved you". Ouch, THAT was hard ! ) Anna Torv sells Olivia's concern ( and horror in the end ) very well, even she hasn't much to do.
This episode had it all : cool Fringe science ( the toxin from the pilot, and the "matter-to-gas" thing, even if I'm a bit disappointed they didn't consider the phasing tech from season 1's "Safe" ), good jokes ( Walter whining about Bell stealing his discs ), cute moments ( Astrid and Walter, awwww .... ). Besides the fact that the plot about Walter's plan is STILL not moving forward, the only thing I can complain about is the recap about Bell's involvement in the beginning : why is Astrid saying all this ? Walter was there, he should remember ! Actually, he even says he does. The writers aren't usually so clumsy with exposition ... That glitch aside, the episode was really great.