Five-Twenty-Ten
Peter, recently having injected one of the Observers' devices in his own body, comes to understand the precognitive abilities that the devices give their owners, but he experiences side-effects, like insomnia. He works with Anil of the human resistance to try to replace one of their briefcases with an identical one containing a bomb. The initial attempt fails as Peter fails to account for all variables, but his second attempt is a success; later, when this Observer meets with others, the bomb that contains a bio-agent gruesomely kills them (later revealed as the same one used in the pilot).Meanwhile, Walter retrieves another tape from the ambered part of the lab. The video instructs the viewer to obtain two of the Observers' "beacons" (as seen in "The Arrival"), which help to fix a point in space and time. The video goes on to point to two stored at Kelvin Industries, where Walter and his former partner William Bell worked previously; the storage area would require Bell's hand print, which explains why Walter had cut off Bell's hand when they were previously released from the amber (as seen in "Letters of Transit").
Walter, Olivia, and Astrid go to the facility to find the entrances blocked by rubble; as traditional means to remove the rubble would be difficult to acquire, the three decide to go to Nina Sharp for help. After a tearful reunion, Nina promises to help them with an Observer device that can sublimate the rubble quickly, though the effect will quickly attract Observer forces to the area. As her aide instructs Olivia and Astrid on the device, she has a heartfelt discussion with Walter. Walter believes that the pieces of brain re-implanted by Etta is causing him to revert to the ruthless man he had been before, and asks Nina if she can see that man in him now, but Nina denies it. He tells her that because he has Peter to keep him grounded, he will not revert. Nina expresses how she tried to save Bell when he was on the path to megalomania, saying that she loved him, but that love wasn't enough to save him in the end. Walter coldly asserts that Bell never loved anyone except himself, especially never Nina, and that she should have known better. She is stunned by this cruel remark, and tells Walter that the good man she knows would never be so cruel and offensive, but that the old Walter would have, and she can see that man in him now. Meanwhile, Olivia expresses concern that she had once lost Peter before after the initial Observer invasion, and fears losing him again.
As Peter rejoins them, remaining evasive about his activities, the device successfully clears the rubble. Inside, they access Bell's laboratory, and Walter discovers that Bell stole his record collection, including a David Bowie album, which he takes back. While searching, they find a combination safe. Walter believes he knows the combination William used for everything (as mentioned in "Jacksonville"), but struggles to remember it, while Olivia insists time is short. Instead, Peter informs Walter he has plenty of time to recall the combination; Walter is able to come up with it (five, twenty, ten), but when they open the safe, there are no beacons; there is only a strange device and, to Walter's surprise, a photo of Nina. Believing the effort was all for naught, they are about to leave when Peter uses the device to bring the two beacons to the surface. Peter confidently exits the building despite Olivia's insistence that the Observers could be waiting for them. However, Peter proves to be correct; he instructs the others to return to the lab while he deals with another matter.
Walter returns to Nina, showing her the photo, and apologizing for his earlier behavior and revealing that Bell did love Nina, though it wasn't enough to save him. He asks her to consider helping him remove the pieces of brain as to revert to his kinder self. Olivia returns to Etta's safehouse to find Peter there, in front of several boards, filled with dates, times, and photos of Observers. He emotionlessly explains that he implanted the Observer's device in his head, had used it to switch the briefcases as to kill several of the Observers who are Captain Windmark's top lieutenants, including those in charge of security such that they would not be detected at Kelvin Industries, and has plans for the same for Captain Windmark, in order to avenge Etta. He demonstrates his new abilities by predicting Olivia's sentences perfectly. Worried, she leaves him to plan, while he discovers that he is starting to lose his hair. Walter, alone with the assembled components from the tape, contemplates to himself listening to David Bowie's "The Man Who Sold the World" from the recovered album.
