It's two in the morning and Olivia and Peter are in separate beds. Peter is restless and cannot sleep because he "had another one of those headaches." Astrid knocks on the door and says that there is something they both need to see. Peter and Olivia follow Astrid into the lab and she tells them that the radio is releasing a code that is like morse code. Olivia wonders if it is Donald and Peter asks how does Donald know that they are still alive. Olivia believes the only way to know for sure what is going on is to find out what the message means. Olivia asks Walter if he recognizes this and when he does not answer, Astrid tells them that Walter can't answer because he dropped acid. Peter approaches Walter, but Walter is having visions of a green fairy and a blonde woman.
Peter asks Walter to concentrate for a moment and Walter whisper back that Carla, is old dead lab assistant is there to haunt him. Apparently, Carla burned in a fire. Peter asks about the sound that the radio is picking up but Walter is too focused on the green fairy. Walter finally says that the message is in his mind and then apologises for being high, saying that he didn't know they were going to get a message and would not have taken the acid. It seems that Walter dropped the acid in a desperate bid to remember the plan. Walter then tells Peter of Nina's promise to once again remove pieces of his brain and his bid not to lose any of them. When Peter tries to reassure him, Walter says that it's not enough and that he is afraid that they are running out of time. Apparently, Walter got dressed and was at the tunnel door and no idea who he got there or what his plan is, so now Walter worries that the next time he won't be able to stop. Walter believes that there must be something left in tact in his brain that he can use. Peter then escorts Walter from the room.
When Peter walks back into the room alone, Olivia asks if they can track where the signal is coming from. She believes that if they can track the source of the signal that breaking the code will be irrelevant. In his room, Walter is still tripping pretty heavily and engaging with the green fairy who hands him a match. Walter lights the match and then lights a candle. He is caught up in the colors of the flame but uses the candle to guide his journey back into the lab, where he sees a frozen image of two men. Walter turns on a tape and sees Astrid, Olivia, Peter and Anya talking about tracing the signal. What Walter does not realise, is that they are all actually talking behind him. Carla then appears again and tells Walter that there is something hidden in the lab.
They turn on the tech to track the signal and in a forested area, there is a gun lying on the ground. The crew drives out to Willington Connecticut. They get out of the car and Peter says that they have to go on foot from there but because the signal is so strong, they don't believe that they will have to travel far. Peter tells Olivia that she amazes him and that he doesn't deserve her, after everything he has put her through. Olivia smiles and then kisses him. When Olivia looks over Peter's shoulder, she spies a little cabin and so they head towards it. They find the bodies of dead observors and a loyalist. Examining the scene, Olivia says that it looks like they were killed in a fire fight and from the decomposition of their bodies, 10-15 years ago at least. Peter walks over to an abandoned truck and finds yet another body and says that he believes they have just found Donald. Peter believes that Donald killed the observors and the loyalists but died of his wounds before he could get away. Olivia wonders if Donald has been dead all of these years, then who sent the signal.
Peter follows a cable which runs up a tree. Inside the truck, Olivia opens the wallet of the corpse they found. When she walks over to Peter, he tells Olivia that what they have found is not the source of the transmission but something being used to amplify the sound. In return, Olivia tells him that the body they found isn't Donald; it's Sam Weiss.
At the lab, Astrid asks Walter about Sam Weiss and Walter says that he has never head of him. Olivia tells Astrid that Sam was someone both she and Peter knew in a different timeline. Astrid asks what Sam had to do with Donald and the transmission and if there is a possibility that Sam was Donald. Olivia says she thinks that Sam was simply helping with the transmission but doesn't think that he is Donald because they have seen glimpses of Donald on the videotape and the hair and body type doesn't match up. Olivia promises to call back when they have something new. Carla appears to Walter and tells him that he is still cold. Walter is frustrated and says he doesn't have time for infantile games. Astrid notices that Walter is talking to himself but doesn't say anything. Carla taunts Walter by saying that the old Walter would go off to the observers knowing that a man with his intelligence and vision would be valued. Walter says that he won't risk the security of everyone he cares about and then rushes out of the room but Carla appears before him again. She tells him that he is burning up and that she knows how that feels. Walter is looking down at his feet and realises that there is a hidden compartment there. When he opens it up, Nina steps forward and tells him to put it back, but Carla says that it's his life work, the work she came to burn. In the corner, Walter sees a burned man looking at him. The green fairy appears but Walter waves her off and opens up the book. Inside he sees diagrams and graphs.
Walter is in a cab looking through the book and the driver turns around and tells he cannot make change for the fifty Walter gave him. He finds design after design and turns to ask Carla what the Black umbrella is but she does not answer. A man dressed as a butler, opens the taxi door and asks Walter if he would like a top up on his acid. Walter decides to indulge again and continues to look through his book and Carla asks him if he remembers when he was going to create his own universe and start from scratch. Walter tells Carla that he is not that man anymore and realises that he is no longer in the lab. Carla tells him that he is in Manhattan, at observer headquarters and that he snuck out of the lab and tricked Astrid. Walter replies that he promised Peter that he wouldn't leave the lab alone again and that he wouldn't hurt the people he loves. Carla replies "you're in denial, you've been him, longer than you've been you. I'm just like this journal, I represent all of the things that you're trying to keep buried." Walter again asserts that he is different now but Carlie says, "It was a surgical procedure which made you different but you can't run from that now." Walter believes that an Observer is approaching the taxi but it turns out that it's Astrid and he is not actually in Manhattan.
They walk together into a marina where they meet Olivia and Peter, who have rented a boat. Walter asks why they need a boat and Peter says that they have tracked the signal to an island. Of course, when Walter looks at the island, he sees a green palace. As Walter approaches the boat, he becomes confused and disoriented. Before they can get into the boat, a group of loyalists pull up and question them about where they are going. Peter and Olivia quickly kill them, as Astrid escorts Walter to the boat.
The team takes the boat to the island safely and Peter uses the tech to check out the source of the signal. Walter again sees Carla but Astrid assures Peter that Walter is fine. The team come across a house and a man walks onto the porch holding a shotgun and asks what they want. Olivia says that they are there to meet Donald and asks if he is Donald. The man replies that there is no Donald there, so Peter points to Walter and asks if the man has ever seen him before. The man holds up his revolver and says, "I don't know who you are but I suggest you go back where you came from." The you observor boy from season one walks onto the porch with a woman. The woman asks Richard, (the man holding the gun) who the team is. Olivia says that they are there because of a man named Donald, who left them a radio which started transmitting a signal this morning, which led them there. The woman tells Richard to put the gun down and says, "Richard we knew that this day would happen and that one day, someone would come for him." Richard tells them that the transmission had a pass code and that Don said the person he left the radio for would know the code. Richard says that if they are who they say they are that they need to give them the code.
Walter has yet another acid trip, which kind of defies a description. When he comes back to reality, he says, "black umbrella, that's the password." Richard lowers his gun and the wife tells them that they need to come inside. The green fairy appears and applauds Walter, as he heads into the house. Inside, Richard says that when the invaders came that they helped the cause to fight them in any way they could. He adds that after awhile, they acquired a reputation of people who could be trusted and that is how they met Donald. Apparently, Donald left the boy for them to watch over and said that he was important to the plan. Donald never came back because he didn't want to put them in danger but before he left, he said they had to turn the radio on every five days, so that it would broadcast a coded message. This was over 20 years ago and in that time the boy (Michael) hasn't spoken and hasn't aged a day. Richard admits that there were days that he never wanted to turn the signal on at all. On the porch, Michael says his goodbyes and leaves holding Olivia's hand.
Back at the lab, Olivia brings Michael a cup of hot cocoa; he doesn't drink it but simply stares. Olivia tells Michael about Etta and so he takes a sip but still does not speak. Olivia asks Michael if he knows her or remember her and he shakes his head yes. Peter points out that Michael is from a different timeline and that it doesn't make sense that Michael remembers her. Olivia points out that observers experience time differently. How is is that Peter does not know that after having spent so much time with observer tech in his brain?
Walter is in a different part of the lab and he is still hearing voices from the past. He also sees visions of the past of him and Elizabeth. He is clearly a haunted man. Carla then appears and tells him that there has to be a line he can't cross, but Walter tells her that his son is dying. Carla points out that for the sake of one life he will destroy the world. We get a vision of Peter in the water, the day Walter brought him over from the alternate universe. Walter gets up and pours lighter fluid over the book and then sets it on fire as Carla watches. Carla tells him that it is too late, now that he remembers all of the things that he is capable of. Nina appears and tells Walter that he has got to continue and that he has got to keep fighting. Carla tells Walter that there is nothing to burn and when Walter looks into the bowl, there is fire but no book. Carla adds again, "you've been him, longer than you've been you." Walter then sees a vision of him looking back at him.
I suppose this episode advanced the plot somewhat. I wonder if maybe Michael is actually November from a different timeline? I am glad that they they are tying up a mystery from season one but I still think the role of a final season is to answer questions that the writers have posed for the entirety of the show not head off in a whole new direction with a token inclusion of mysteries from the past.
The best part of this episode was Walters acid trip. I particularly loved the trip he went on, on the island. I do however the idea of dealing with Walter's changes after having to put up with a few episodes of Peter changing is a bit much. I am also really irritated after the big deal that was made of Peter inserting the tech in his brain that there wasn't much of a consequence.
Astrid once again was Walter's caretaker and only left the lab because Walter needed and escort because he was high. Yeah, I'm not surprised but I continue to be irritated that Astrid continues to be treated as though she cannot possibly add anything of importance to the team, beyond babysitting Walter. I am further irked that Walter can only be arsed to give Astrid a compliment when he is high.
