The Recordist

As the rogue Fringe team continues to fight off the oppressive Observers' invasion, unforeseen events lead them into a forest where they encounter a strange subculture of people devoted to recording human history.

Synopsis provided by the Fandom Wiki, Fringepedia, and Wikipedia.

• Timestamp: 20:13
  Donald entered the mine 5 weeks after the invasion and took some rocks. He was described as being in his late 30s, medium height, dark hair. Donald said he was waiting for "a colleague, a scientist from Boston, to meet him." Observers found him and took him away.
• The coordinates recited by Walter in his video recording included the 49th parallel. The 49th Parallel is a Canadian WWII film that was released in the United States as The Invaders (the term the Recordists used to identify the Observers) and starred Raymond Massey, who shares his surname with Edwin Massey, the titular Recordist.

• Timestamp: 17:57
  They ate chewable apple tablets instead of fresh apples.