If it wasn't for a great and moving performance by Christopher Lloyd and the beautiful representation of the chemistry between Lloyd and Noble, I would have rated this episode to be the most disappointing one after Brown Betty......
Why? Well, here's why:-
The 10th episode of Fringe in the last 2 seasons have always been the most interesting ones in terms of the mythology, Season 1's 10th episode showed the shocking teleportation scene of Mr. Jones, which had set the pace and mood of Fringe. Season 2's 10th episode revealed a huge plot about Walter's brain and who removed parts of it, along with hinting at what Walter could be WITH those tissues (and memories) back in his brains. Considering that, what in the blue hell did this episode offer???
It din have the intrigue and knowledge of a typical standalone, neither did it have any MAJOR significance of a mthyological episode. The entire angle of Bobby and his father seemed entirely FORCED considering what the observer wanted to do, I mean there are many ways to check if Walter could sacrifice Peter or not.......not to mention the whole "He is still alive" angle was also quite stupid, as Peter himself says, "There are many different ways he could have saved your life walter", I dont think Walter's justification of "they are not humans" was not at all satisfactory and seemed more like a convenience typically used by mediocre writers
There was no IMPACT revelation in such an important episode, no new answers either.....when the episode started, I was really excited as I thought they are going to connect Bobby's death and Peter very beautifully in terms of the mythology, but it ended up being as a stand alone forced angle. I also thought that there will be more insights about Walter's missing memory but even that wasn't to be.
All in all, I would give this episode a 6/10 and all 6 goes to Noble and Lloyd's amazing acting and chemistry....otherwise, as a 10th episode storyline part, it was a major DUD