Most people don't get a chance to find out if they've had an impact on history. However, this week the Fringe team did. They also learned something about heroes and what makes them.
As the episode begins, the team has found another of the six tapes Walter needs to remember how to get rid of the Observers. However, instead of the second tape, they discover the third. Astrid thinks Walter purposely stored them out-of-order to throw the Observers off if they found them.
The team, except for Astrid, follows the tape's coordinates to a remote location on a woody mountain. Once they get there, they can't find what Walter left. What they do find is a colony of humans who've taken refuge from the Observers.
All of them are suffering from a strange ailment that makes their skin look like tree bark. The team learns they've been exposed to it as well.
One of the colonists recognizes Walter, Peter and Olivia. Shocked that he does, Walter asks him how. The man takes him to a place where they've managed to store much of the history between the time the Observers took over and the present.
He tells the team that they are part of that history. His son shows Olivia and Peter comic books he drew about their team's adventures.
For some reason, that saddens Olivia and she gets distant. When Peter asks her a question about something from their past, she says she doesn't remember. He knows she does because she never forgets anything.
Back in the lab, Astrid is still trying to get all the information off the tape. She learns enough to tell the team that they are looking for a mine.
Walter asks his new friends about that and they take him to a gold mine. Once there, they discover a cavern with a rope leading down into it. They pull on the rope and haul up a dead body. The man died of the same disease effecting the rest of the colonists.
Walter hypothesizes that the mine is the source of the illness and advises the colonists to steer clear of it. While he and Olivia are both infected, the disease hasn't yet taken root deep in the skin so he's able to remove the bark-like coating.
Knowing they need to get into the cavern, Walter begins making a suit that will allow them to go there without risking further exposure. Meanwhile Astrid learns from the that they're looking for quartz rocks. Unfortunately, they need 40 pounds of them.
A call to the camp from a supposed loyalist informant, lets the group know the Observers are tracking them. Because of that, the colonists demand that the team leave right away. They can't risk discovery of their camp because of the history they keep.
The little boy becomes shocked that his people, especially his own father, is refusing to help. The father explains to Peter that he's not afraid of dying. He's afraid of losing what he has left: his home, his people and his son. Peter understands.
So does Olivia. She tells Peter that she does remember the incident he brought up earlier. That's when she tells him she wasn't a hero going back to fight the Observers. She was a coward, running away from what she feared they'd find together—their daughter dead at the Observer's hands.
Peter tells her to let go of her disappointment in herself. He says their family has a second chance and he plans to take it. She nods her head in agreement.
Ultimately, the man decides to help them. He calls a neighboring colony asking to barter for the copper Walter needs to finish the suit. Then he goes to talk to his son to say goodbye. At the last-minute, though, he gives the team a map to get to the camp. He tells them he isn't going with them. Is he a coward after all?
No, he's not. The map is a decoy. The man goes down into the cavern alone to recover the needed rocks because he couldn't get the copper Walter needed to finish the suit. Unfortunately, the disease overcomes him and he dies there.
The rocks in hand, the team heads away from the camp just as the Observers draw closer to their van. When their enemy surrounds it, though, Fringe isn't inside. It's a man who says he found the van abandoned on the side of the road. The team has managed to elude the Observers once again.
As the episode closes, the little boy goes to the history room and makes a data crystal about his father. He says "a recorder of history made history himself today". Then he outlines the bravery of a single man, accepting his death so he could help others.