In the episode, the Man in Black (Terry O'Quinn) executes his plan to destroy the island as Jack Shephard (Matthew Fox) tries to stop him once and for all.

One by one, each protagonist begins to recognize one another based on close contact with a person or object that was important to them throughout their time on the island, receiving flashes of memory.

Arriving there, Sawyer is confronted by Ben Linus (Michael Emerson) and the Man in Black (Terry O'Quinn), who reveals his plan to destroy the island.

At the same time, Desmond, having been rescued by Rose Henderson (L. Scott Caldwell) and Bernard Nadler (Sam Anderson), is confronted by the Man in Black, who has Ben with him.

Meanwhile, Miles Straume (Ken Leung) finds a no-longer-ageless Richard Alpert (Nestor Carbonell) in the jungle, and they set out by boat to destroy the Ajira plane which would allow the Man in Black to escape.

Kate and Sawyer travel to Hydra Island via Desmond's boat Elizabeth, to the site of the Ajira Airlines plane where Lapidus, Richard, and Miles have been quickly trying to make it air-worthy.

[13] They have expressed satisfaction regarding the finale; Daniel Dae Kim stated "If you think about how many pieces the writers had to put together in order to make it fall into place, it’s mind-boggling, and they did such a great job... For me it was very satisfying.

"[16] Instead of being displayed along with ABC promotional material (which in most cases would consist of a preview of the next Lost episode), the finale's closing credits are shown alongside various shots of the Oceanic 815 plane wreckage.

ABC independently decided to add the footage as a soft, nostalgic transition between the final scene and upcoming local news broadcasts.

[18] An ABC source reported that the DVD and Blu-ray release of season six will feature twenty minutes of additional scenes, some of which will have answers to questions, cut from the storyline because of running time.

[19] All former series regulars who appear (Jeremy Davies, Maggie Grace, Rebecca Mader, Elizabeth Mitchell, Dominic Monaghan, Ian Somerhalder, Cynthia Watros) are restored to the main cast in this episode.

In Ireland, RTÉ Two decided to air it on Monday, May 24 at 9 pm rather than its usual Thursday night slot in the interest of fans who did not want the ending to be spoiled.

[29] In its original American broadcast, "The End" was viewed by 13.5 million households with a 5.8 rating/15% share in the 18–49 demographic, coming first in every time slot and boosting ABC to the highest rated network on Sunday.

[35] Of the most positive reviews, IGN writer Chris Carbot gave the episode a score of 10/10, describing it as "one of the most enthralling, entertaining and satisfying conclusions [he] could have hoped for.

[38] James Poniewozik of Time also praised "The End", calling it "full of heart and commitment";[39] Zap2it's Ryan McGee described the episode as "a masterpiece.

"[43] Not all critics were satisfied with the episode: the British newspapers The Guardian and The Daily Telegraph both reported that "The End" received negative reviews and disappointed its viewers.

[46] Mike Hale of The New York Times gave "The End" a mixed review, as the episode showed that the series was "shaky on the big picture".

[48] David Zurawik of the Baltimore Sun gave the episode a highly negative review, describing the final scenes as "wimpy, phony, quasi-religious, white-light [and] huggy-bear".

He added: "It looked like [Jack] was walking into a Hollywood wrap party without food or music – just a bunch of actors grinning idiotically for 10 minutes and hugging one another.

Tim Teeman in The Times referred to "a global scratching of heads" in his review but concluded "The questions are ceaseless: it may be healthier, as one online fan put it, 'to just accept it and move on'".

[58] Steve Busfield and Richard Vine of The Guardian spoke positively about the episode, saying that the series would "continue to baffle, infuriate and delight fans for an eternity".

[44] Conversely, the TV critic Charlie Brooker, also writing for The Guardian, remarked that "The End"'s plot "made less sense than a milk hammock",[59] while the comedian Danny Baker called the episode "an outrage".

[2] Indiewire similarly branded the finale as the number-one worst ever, criticizing it for being "unbelievably long" and having a "decided lack of dramatic tension and any real thrills".

[60] Daniel D'Addario, writing for Salon.com, listed "The End" as one of the "worst finales ever", describing the series as "a show whose twists and turns didn't always seem to be undertaken by people who knew what they were doing.

[62] Danny Walker of the Daily Mirror listed the episode as one of the seven worst TV series finales, saying that it "left viewers with even more unanswered questions".

[63] In 2019, Kelly Lawler of USA Today named the episode the third worst series finale, describing the ending as "easy" and "schmaltzy".

Writing in September 2014, Tom Eames of Digital Spy defended the finale, explaining that, although "divisive and controversial", it was "a beautiful piece of television".

"[65] Cory Barker of TV.com also retrospectively reviewed the episode positively, naming it one of his all-time favorite series finales, and describing it as "emotionally satisfying" and "jam-packed with amazing moments".

[67] A decade after the series wrapped, Justin Kirkland of Esquire praised the finale, describing it as "on par, and expected from some of the greatest television of today".

[69] In 2021, 11 years after the episode was broadcast, respondents to a survey conducted by the website OnBuy.com name "The End" as the most disappointing series finale ever, with its receiving 27.3% of the vote.