September is an Observer. His real name is unknown, as September is merely a code designation. Like every Observer, September is bald and lacks eyebrows. He is a member of the scientific team sent to do reconnaissance throughout history. However, he did much more than observe. In fact, one simple mistake had devastating effects, altering the entire fate of humanity and catalyzing most of the events that brought the Fringe team together.
September is a scientist from a possible future in the 27th century. He is one of a species that is an evolutionary descendant of humans called "Observers", a term coined by Fringe Division. The Observers' goal is to use time travel to study key moments in time leading to their evolution, and ensure that certain events played out as they wish. This study is a form of reconnaissance for an invasion of past-Earth, which took place in 2015.
At the time of his discovery, the team was unaware that there were many of these scientists, as he is nearly indistinguishable in appearance from his contemporaries. As a result, they tended to call him "The Observer". The name "September" is merely a codename, similar to the codenames given to all of the other scientists. Each codename refers to a month in the year.
Altering The Timeline
September believed he was merely fulfilling his duties as a scientist when he went to Walternate's Harvard Lab in 1985. It was here that he expected to witness the man discover the cure for Peter Bishop, who was dying. Instead, however, September accidentally distracted Walternate. Walternate turned to look at his unexpected visitor and missed the indicator color-change in the compound that signaled the cure had been successfully created. By the time September left, the indicator had vanished and Walternate missed the chance to cure his son.
September expressed his concerns to his fellow Observers. They acknowledged that September's actions would be dangerous. He had inadvertently changed the outcome of the timeline. Peter Bishop, who should have lived, would now die. This could not be because even one life could dramatically alter the timeline.
Walter Bishop of the Primary Universe crossed over to administer the cure to Peter himself. He took Peter with him back to the Primary Universe. However, tragedy struck and the two plummeted through the ice on Reiden Lake immediately after crossing universes. September saved both of them from drowning. He explained to Walter that one day, he would need a favor from him and then disappeared, and gave him a brief demonstration of his ability to read minds. Witnessing the strong bonds of love between a father and son, Walternate worked tirelessly to save his dying son and Walter crossed universes to save the same boy, stirred something in September. He came to the realization that his own son was important to him, a trait Observers had abandoned long ago. He seemingly came to this conclusion while he was in the car with Walter. Vocalizing his thoughts, he said, "The boy is important. He has to live." He was referring to his own son, but Walter took it to mean Peter was important.
September believed that his intervention would be the end of the problem forever. He was dramatically wrong, however. Walter's crossing over had been unnatural and broken the barrier between both universes, setting them on a collision course. The two worlds were now headed for war- a war that was never meant to be. Perhaps even more drastic, Peter Bishop's life played out very differently, as he was now a resident of an entirely new universe. The consequences of this would not be felt for many years.
September continued to watch important moments in history and, especially now, the new set of probabilities he himself
set into motion the night he distracted Walternate. These moments were coined "The Pattern" by Fringe Division. They were a result of the decaying barrier between universes and allowed for impossible fringe science to unfold on these "soft spots" between realities.
Olivia Dunham noticed September during her investigation of the beacon. Bringing his presence to the attention of Phillip Broyles, she learned from him that the FBI had been tracking his presence for many years.
The Beacon was being hunted by John Mosley. Fearful of the consequences if Mosley were to obtain it, yet hesitant to intervene again, September enlisted in Walter to hide the beacon from Mosley. He later observed as Mosely was defeated by Fringe Division, but was attacked by Peter Bishop in the process. However, he was able to escape before being detained, although he revealed to Peter his telepathic abilities.
Later on, September appealed to Walter again to stop David Robert Jones from crossing over to the other universe. Jones was intent on meeting up with William Bell and initiating a plan to collapse both universes, which would allow him to prop up his own universe in the process. September took Walter to the Bishops' beach house, where he led Walter to a device that would close the portal to the Other Side.
September continued his studies, constantly watching the Fringe Division, taking notes, and photographs.
In "August", one of September's contemporaries, codename "August" kidnaps a woman, Christine Hollis, before she can die in a plane crash. August later has a meeting with his superiors and September, and they scold him for saving her, as she was supposed to die and is not "important" to history. They inform him that this problem will soon be corrected by sending a special assassin, Donald Long, to kill Christine. With the assistance of the Fringe Division, August saves her from the assassin but is mortally wounded in the process and recovered by September before he can be interrogated. As August is dying, September questions August as to his motivation for saving Christine, and August reveals he fell in love with her after watching her for her entire life, and he asks if Christine will now be safe. September comforts him by informing him that Christine is now "important" to history, as she is indirectly responsible for the death of an Observer, and will, therefore, be allowed to remain alive. He watches August cry as he succumbs to his wounds.
In "Fracture" he is seen taking information from a special courier, in the form of a briefcase. An AWOL Colonel, Raymond Gordon, discovers the existence of the Observers and attempts to attack their couriers using human bombs.
After Walternate successfully crossed over and returned to the Other Side with Peter, September appeared to Olivia in "Over There: Part 1", and left a cryptic message, warning her of the events to come in the form of a picture of Peter activating The Vacuum.
September instituted a plan meant to save Walter from drinking a poisonous compound. His plan was two-fold: It would allow him and the other Observers to see whether or not Walter would be willing to let Peter go, as well as save Walter from drinking the compound. It was Peter who drank the compound, but Walter was able to instruct Olivia how to create the cure, as he was the only one who knew how to do it.
After Peter activated The Vacuum and created a bridge between the universes, September went back in time and did not save Peter from drowning in the lake. This caused Peter to be erased from existence.
After traces of Peter began bleeding back into the new timeline, September was tasked with completing the process and erasing him from time for good. However, even after gathering all of the appropriate materials, September, in what appears to be an act of rebellion, decided not to complete the procedure. Peter returned back into the timeline fully soon after. ("Back to Where You've Never Been")
Ultimately, September was kidnapped and shot by Jessica Holt. Olivia and Peter tried to save him and questioned him about what he meant when he told Olivia she was meant to die in all possible futures. Not recalling this, September realized that the moment in question hadn't happened to him yet. He decided to travel through time to discover what he could have meant. He was referring to Olivia having to die at the hand of Walter to stop William Bell from collapsing both universes. After discovering this, he went back in time, ensuring a self-fulfilling prophecy, warning Olivia that she must die. Bleeding out and seeing his life limited, September quickly disappeared.
September resurfaced in Walter's lab, still suffering from the gunshot. Through a synaptic transfer, September revealed to Peter his history. He shared memories of how he had set the entire timeline off-course by distracting Walternate.
He also shared the existence of Henry Dunham, whom he explained was never meant to exist. This event was the final contamination that he could allow. It would irrevocably alter the entire timeline, so he had to erase Peter from time and attempt to set things back on track. He revealed that Peter needed to be with Olivia from the Primary Universe to put everything back on track. He was snatched away by the other Observers and locked out of the universe.
Before he departed, September implanted a code into Peter's iris. This code led Peter to the beacon, which shone a light that guided a healed September back into the universe. He confirmed to Peter that he was in the right place, that Olivia was indeed Peter's Olivia, and disappeared.
September resurfaced again to warn Walter that the other Observers were coming. According to Walter, the two developed a plan to rid the world of the Observers.
September began to help Walter create a plan that would rid the world of Observers. As punishment for his continued intervention, the Observers removed September's tech, which resulted in him becoming a human being with emotion. The first film September and Walter watched together was "Singin' in the Rain," prompting September to go by the name Donald O'Connor. He continued to help Walter with the plan until he was taken away by Observers in Pennsylvania. They could find no evidence incriminating "Donald," and instead placed a tracker on him. Donald's son, Michael, was an instrumental part of the plan, as he and Walter intended to send him forward to the year 2167 to change the future evolution of the Observers. Donald and Walter stored Michael in a Pocket Universe to keep him safe. At an unknown time, however, Donald returned for his son and instead put him in the custody of a family on a remote island. He disappeared shortly after and was presumed to be dead.
After Walter's memories were restored by Michael, he went into the sensory deprivation tank to try and locate September. He had a memory of the New York City landscape and was able to locate September's position. The Fringe Team tracked him down and met with him in his apartment. September revealed much about the plan, including his relationship to Michael, as well as much about the Observers' origins. They went off to retrieve the last pieces of the plan. While in the storage area, Donald and Walter spoke. It is here the Donald revealed that his comment "the boy has to live" in 1985 was in reference to his own son, not Peter. Once the pieces were obtained, Donald explained that he had some last minute business to attend to, promising that he would meet up with the Fringe team soon. When he returned to the lab, the team had gone to retrieve Michael, who had been captured by Windmark. Donald begins building a machine as part of the plan, but a piece of tech he had recover was no longer functioning. He enlisted the help of December to find a replacement. Before the plan is initiated, Donald decides to take Walter's place in taking Michael to the future. However, as the plan is in effect, Donald is shot while leading Michael to the portal and Walter resumes his original role.
- The Observer is very similar in behavior to the G-man from Valve Software's Half-Life series. In the Half-Life 2 game, in particular, G-Man can be spotted in the background of scenes, on monitors, and occasionally players need to use tools such as binoculars at the exact moment to spot him.
- In September 2009, an unofficial FOX press release for "The Arrival" named the character September. The name, an error, was retracted almost immediately in a second press release. However, the character himself confirms in Season Four that September is his code name.
- September appears in the background of every episode for the first three and most of the fourth seasons. In episodes that he does not appear in, another Observer or Observers do.
- A recurring background character based on September appears in the Wikipedia:My Little Pony: Friendship is Magic comics.
- The Observer can be seen on Sports T.V shows or advertisements on FOX.