In this episode, Walter consoles himself after Peter's disappearance by smoking a strain of marijuana called "Brown Betty." Most of the episode is then told from his drug-addled perspective, in which Olivia is a 1940s noir detective and Peter is a con man who ran away with Walter's glass heart.
This episode's glyphs spell:
Walter's fairy tale was about how Peter Bishop stole Walter's heart.
In addition to featuring in Walter's fairy tale, the Observer can be seen at the end of the episode watching Walter return home without Peter.
"For Your Healthy Heart!", written on an egg carton in 'The Man from the Other Side', foreshadows Walter's tale of a broken heart in 'Brown Betty'.
Walter's game of Operation in 'Brown Betty' foreshadows the makeshift medical procedures in 'Northwest Passage'.
Roughly 15 years later Ella was a Fringe agent.