8. And Those We've Left Behind (Season 4, Episode 6)
That previously mentioned first arc of the fourth season, in which Peter is erased from the timeline but reappears thanks to the Power of Love, is admittedly a love it or hate it affair. Even as someone who enjoys the Olivia/Peter relationship, I found it slow-burning at the best of times and glacial at the worst. Nonetheless, And Those We've Left Behind is one of the best demonstrations of Fringe's confidence in treading the line between sentimentality and genuine emotion. While the episodic plot is in itself heartrending a scientist tries to prevent the loss of a loved one, because it's Fringe it is elevated by the understated performances of real-life married couple Stephen Root and Romy Rosemont, who sell their partnership brilliantly. Still, we were all waiting on the interactions between Peter and this timeline's Olivia and Walter, and this episode certainly delivers. Olivia is once again distant but professional, and Walter is downright antagonistic to his son, whom he won't believe is the real thing. Framing Peter's dilemma about his own place in this world without those he loved within a storyline which is simply a meditation on loss and love is just the sort of thematic resonance we'd come to expect from Fringe, and after a few lacklustre opening episodes, it was welcome.
