The episode launches on the campus formerly known as Harvard. Astrid is operating the laser within the amber, with Walter harping at her all the while. The object of their search: a tape. They succeed in liberating it just as Peter and Olivia return with the news that they’ve obtained fuel for the van.

The bad news is that the first tape is number three. The tapes were stored out of order. TV Walter gives them a set of coordinates. Etta asks to hear them again, but Olivia is able to recount them. Now we know that photographic memories are not as genetic as we’d like. Bummer. On the bright side, Etta is able to call up a map of the location, but Walter does not recognize it.

This leads to Northern Pennsylvania, a quiet and woody area. When they reach the coordinates, however, nothing is in sight…until, of course, they spot someone watching them from behind a tree. The creeper, realizing that he’s been spotted, runs away. They follow, only to be ambushed by muddy, gun-wielding guerillas. That’s always exciting.

The guerillas parade our heroes into their camp, an assortment of tents, folding chairs, and solar panels. The guerillas search them and confiscate their weapons, which would be easier if Walter did not seem ticklish. Luckily, they are recognized by a man wearing glasses, who seems happy to see them.

Oh, and apparently, they’re not muddy. They’re scabby. And that’s disgusting.

The one wearing glasses, Edwin, takes them to a cellar, some kind of facility where “data cubes” are stored (for fellow cartoon geeks, It’s very reminiscent of the little globes in Superman’s Fortress of Solitude in the old animated series. Each cube shows a piece of history since the time of the invasion).

Edwin explains that the skin condition has to do with the area, but by the time they realized it, it was too late to leave. They cannot travel without being recognized. Edwin encourages Walter to leave, but Walter cannot go without finding the piece of the plan. To help, Edwin begins searching for documentation that Walter has come there before.

Meanwhile, Edwin’s son, River, gets to know the Fringe team. He asks them to sign the comic books he made about them.

Astrid, who is still at Harvard, is going over the distorted parts of the tape. After cleaning it, she learns the team is looking for a mine. Great news, everyone! Cell phones still work! Even better news: there’s a gold mine nearby.

On the downside, the Observers have just figured out where our heroes are…

Down in the gold mine, our heroes search for clues. Etta finds a rope that goes down a shaft. Together, she and Peter work to pull it up. And, lovely! It’s a nice yucky skeleton. Like the people they met, it’s covered in bark-like scabs. Apparently, they’ve found the location of the condition. (Fortunately for them, being main characters requires being photogenic, so even if they get the scabs, they will either be short-lived or in a spot not usually seen.)

I’m sure they would all be unhappy to know that a soldier has just tipped off some random, creepy person that Etta has been located.

Once back in the woods, the team works to run tests on the body. It seems that the scabbing, even though it’s an evolutionary defensive mechanism, suffocated the victim. Edwin interrupts to tell them that, years ago, a man named Donald came to collect red rocks. The man claimed he was waiting for a Bostonian scientist. Unfortunately, Donald was caught by the observers.

Even more unfortunately, there is a small scab on the back of Walter’s hand. And Olivia’s neck. No worries—they’re smaller than dimes. Of course the scabs have not rooted into their skin, so they are easily removed.

Walter decides to build a suit that will allow him to enter the mine, sending Olivia to the van for supplies. But there is a camp they’ll need to visit to obtain everything. Just then, Etta gets a call. The creeper who got the call from the guard has called to warn her that they are being tracked.

At the van, Peter and Olivia recall the time when Etta was missing. Olivia confesses to feeling responsible for their daughter’s disappearance, that Etta vanishing was punishment for her lack of maternal instincts (well, she is pretty robotic most of the time). Apparently, she parted from Peter because she could not bear the thought of finding Etta’s corpse. Peter points out, however, that they are receiving a second chance. What a softie.

Etta finds them and warns them that they’re being traced. When they tell Walter, Edwin insists that they leave. He wants them to make the suit in Boston and then perhaps come back, but Etta is worried that the Observers will seal the mine. Edwin has had radio communication with the camp they are trying to reach, but he is reluctant to help.

Peter talks to Edwin, tells him that the rocks they want to retrieve will somehow help them defeat the Observers. At last, Edwin agrees to contact the mine people on his radio. Around that time, soldiers locate tire treads that will lead them to the van our heroes are driving. On the plus side, Etta spots them coming.

Now comes the moment where Edwin has to explain to his son that he is going on a mission from which he might not return. After some moving dialogue, Edwin goes forth to meet his fate.

More cleaned tape footage has arrived from Harvard (or at least I assume that much, because suddenly they’re watching it on Etta’s device). It seems that the mineral they are looking for is the key ingredient for a powerful energy source. TV Walter reveals they need 40 pounds of the rock. The writers reveal that it is indeed Astrid who is transmitting the footage.

Unfortunately, Edwin chickens out at the last second. He gives them materials to trade with and wishes them luck. Darn. There goes our red shirt.

When they reach the coordinates, however, there is nothing there. Edwin has sent them on a wild goose chase while he goes to the mine himself. There he is met by an older man.

Cut back to the camp, where Walter and Etta are waiting. They hear a loud noise come from the mine. When they rush to investigate, they find the old man. He tells them that Edwin has gone into the mine. Inside, they find a bucket full of the red rocks. At the bottom of the shaft, they find Edwin petrified.

We next see the van driving away, but it’s not our heroes. It’s a man who found it abandoned. Meanwhile, the Fringe team hotwires an old car and makes their escape.