The fifth and final season of the American Fox science fiction television series Fringe premiered on September 28, 2012, and concluded on January 18, 2013.

[3] J. H. Wyman served as a sole showrunner during the last season, with four other writers: Alison Schapker, Graham Roland, David Fury and Kristin Cantrell.

Previous series regulars Lance Reddick, Blair Brown and Seth Gabel returned as special guest stars.

The opening sequence for the season retains the one featured in "Letters of Transit", with terms including community, freedom, joy, imagination, individuality and free will.

The hunt for the tapes which contain the plan to defeat the Observers, serve as the way to contain one story into one episode, thus creating a procedural side of storytelling.

They said that the finale satisfied hardcore fans, created a great integration of elements from previous seasons and made a natural conclusion for the characters.

September "partitioned" the plan in Walter's brain to make it impossible for anyone to retrieve without the use of a thought unifier, a piece of Observer technology.

They are recovered by Etta Bishop, revealed to be Peter and Olivia's adult child who had gone missing during the Observer invasion, and while a Fringe division member, also working with the underground along with Broyles.

This would have soon caused his brain to sacrifice areas dedicated to feelings and emotions in order to increase space for intellect and logic, which is what happened to the Observers originally - and would have been an irreversible process.

September further reveals that Michael is his "son", grown in the future from his genetic material but had his maturation halted when it was discovered that his brain is different from other Observers' — capable of both superior intelligence and deep emotions.

As Captain Windmark and the Observers close in, Michael allows himself to be captured and taken to the high-secure facility on Liberty Island; Olivia takes Cortexiphan to allow her to jump to the parallel universe, travel safely to the open Liberty Island there with the aid of her doppelganger Fauxlivia and her friend Lincoln Lee, and jump back in the same manner.

Though Michael is recovered, September finds the core initiating reactor for the time machine is insufficient, and pleads with December to get a new one from the future.

September offers to take Michael instead, having come to appreciate his role as a father, but he is shot by a stray bullet as they set up the wormhole, while Olivia, enhanced by the Cortexiphan, uses the power to smash Windmark between two cars and kill him.

[17] Wyman announced that season five only was employing four writers, himself, Alison Schapker, Graham Roland, and David Fury.

Michael Cerveris reprised his role as a human version of September, Donald, in "Anomaly XB-6783746", "The Boy Must Live", "Liberty" and "An Enemy of Fate".

Among the other guest actors were Paul McGillion as Edwin Massey ("The Recordist"), Zak Santiago as Cecil ("Through the Looking Glass and What Walter Found There"), Gabe Khouth as Dr. Darryl Hastings ("Five-Twenty-Ten" and "Anomaly XB-6783746"), Tom Butler as Richard, and James Kidnie as The Commander (last three episodes).

Jenni Blong reprised her role as Dr. Carla Warren in "Black Blotter", after previously appearing in the second-season episode "Peter".

Eugene Lipinski reprised his role as December the Observer in the final two episodes; he previously recurred in seasons two to four.

But if those things don't matter to you, or if you were just more invested in the rich characters and their journey and finding out if they found the peace they deserved, or if you're okay with having ambiguous conclusions, then Season 5 was probably pretty damn good in your opinion.

The website's critical consensus reads, "Fringe overcomes a compressed episode count and humbled production values to deliver a moving and rousing conclusion to its fans.

[37] After watching the "Transilience Thought Unifier Model-11", Matt Roush of TV Guide wrote that "this endgame for one of TV's most adventurous sci-fi fables is staged as a battle for mankind's survival against the invading Observers, who've poisoned the environment and eradicated hope: "Nothing grows from scorched earth," one Observer remarks.

Fringe has always grounded its bold and entertaining imaginative storytelling in deep emotional realities, and this is especially true as time-tripping Peter (Joshua Jackson) and Olivia (Anna Torv) reunite with their now-grown daughter Etta (Georgina Haig), a resistance leader, while continuing to fret over Walter".

[38] Mike Hale of The New York Times also stated that "no matter how drastic the swings between seasons, an overall consistency has been maintained, helped by the tight focus on a relatively small number of relationships.

"[39] Chris Cabin of Slant Magazine criticized the final season saying that "as Fringe's ambitions have grown, the sense of real risk, danger, and punishment have diminished to close to nothing as the series nears what will likely be an inadequate conclusion".

[35] Ken Tucker of Entertainment Weekly gave the whole series a very positive review, saying that "in the end, Fringe — which concluded with a back-to-back, two-episode wallop on Friday night — fulfilled nearly every promise it made to its audience over the course of five seasons.

It remained true to its core values: the primacy of family, the sacredness of trust, the joy of a good joke, the exhilaration of intellectual inquiry, and the jolting power of love", and concluded with a thought: "This is the legacy of Fringe.