"The Firefly" is the 10th episode of the third season of the American science fiction drama television series Fringe, and the 53rd episode overall. The episode centers on a chain of events created by Walter's crossing over into the parallel universe in 1985 that has had subtle but significant effects in the present. Christopher Lloyd guest-starred as retired rocker Roscoe Joyce.
As the first episode in its new Friday time slot, "The Firefly" aired on January 21, 2011, in the United States to 4.88 million viewers, outperforming the previous episode "Marionette" Thursday night viewership by 18%. Time shifted viewership added 42% in its ratings. It received generally positive reviews, with many praising the storyline as "elegant" and "beautiful."
Plot
The Fringe team is brought to a nursing home, where Roscoe Joyce (Christopher Lloyd), the former keyboardist of the band Violet Sedan Chair, was seen talking to his son Bobby (Nick Ouellette) who had died in 1985, as well as evidence of an Observer. Walter Bishop (John Noble), meeting his musical hero, requests to take Roscoe back to his lab to help Roscoe remember what his son said. Walter is able to help Roscoe remember much of his past since the loss of his son through therapy that includes helping Roscoe to recall his piano-playing skills. Roscoe shortly recalls the conversation with his son, which was actually a message from the Observer September to Walter. September (Michael Cerveris) soon appears at the lab and requests to speak to Walter.
As they walk, September reminds Walter of the damage he did when he brought Peter from the parallel universe. September recounts the events of one such chain: in the prime universe, three months after Walter's crossing, Peter (Joshua Jackson) captured a firefly which set into motion a chain of events that eventually led to the death of a pedestrian in a car accident (Walter brought over Peter, Peter caught a firefly, a little girl nearby didn't catch that same firefly, she wandered away, her father drove around looking for her, he hit the pedestrian). September mysteriously departs when Walter answers a telephone call, but not before leaving him with a message: "give him the keys and save the girl." Later, Walter returns Roscoe to the nursing home. Roscoe thanks him and explains that the recent events reminded him of the last phone call he had with his son, where Bobby said he had dreamed of meeting Roscoe in a nursing home in the future. Roscoe is remorseful that Bobby died shortly after that call when a car struck him while crossing the street, which led to the breakup of the band. Because of the date and place of the accident, Walter realizes that Roscoe's son was the pedestrian previously mentioned by September.
Unbeknownst to the Fringe team, September has engineered several events in the last few days, including stopping an armed robbery to help the asthmatic female employee (Olivia Cheng) recover from an asthma attack, taking her inhaler. When Walter hears of this witness, he requests Peter and Agent Olivia Dunham (Anna Torv) to bring her to his lab, believing her to be related to the Observer's warning. Minutes from the lab, September rams the car in which the woman is being transported, initiating another asthma attack. September races from the scene, prompting Peter to follow him in Walter's car, requesting Walter to "give me the keys and save the girl." Walter realizes that September has been orchestrating the events leading up to this point and urges Peter not to go, believing that following the advice of the Observer might lead to Peter's death. Walter eventually relents and returns to help the woman, creating a makeshift inhaler before emergency help arrives. Meanwhile, Peter and Olivia follow the Observer to a rooftop. Peter corners September, who says "It must be very difficult, being a father", before he shoots Peter with an energy blast that knocks him off his feet. Olivia arrives in time to give chase to the Observer but September disappears from an adjacent rooftop.