WatchmenSave

The film opens in an alternate-history 1985 New York City. The United States has won the Vietnam War with assistance from a superhuman called Doctor Manhattan; Richard Nixon is serving an unprecedented fifth presidential term; the Cold War is approaching nuclear catastrophe; costumed vigilantes have been outlawed by the Keene Act for nearly a decade. A retired vigilante named Edward Blake, formerly the violent government-aligned hero called the Comedian, is murdered in his Manhattan apartment, thrown through his high-rise window after a brutal struggle. The opening title sequence, set to a contemporary song selection, depicts the alternate-history rise and fall of America's costumed-vigilante movement across four decades through a series of stylized tableaux.

Rorschach (Jackie Earle Haley), a still-active masked detective who refuses to comply with the Keene Act's outlawing of vigilantes, investigates Blake's murder despite the police having no leads. Rorschach wears a constantly-shifting black-and-white inkblot mask that he calls his face, and narrates the film through a journal he keeps. His investigation suggests that someone is systematically eliminating retired masked heroes. He visits the surviving members of the original Watchmen team to warn them: Daniel Dreiberg / Nite Owl II (Patrick Wilson), an obese-aging-into-flabby suburban widower who has retired into hobby-electronics; Adrian Veidt / Ozymandias (Matthew Goode), the world's smartest man who unmasked himself publicly years ago and has built a billion-dollar peace-promotion business empire; Laurie Juspeczyk / Silk Spectre II (Malin Akerman), the daughter of a previous Silk Spectre who has been romantically involved with Doctor Manhattan; and Jon Osterman / Doctor Manhattan (Billy Crudup), a fully blue-skinned godlike physicist who can manipulate matter at the quantum level.

Doctor Manhattan's backstory is given the film's most extended flashback sequence. Jon Osterman was a young Princeton physicist who was accidentally trapped inside a particle-physics chamber in 1959 and physically dissolved into atomic constituents. Over the following months his consciousness reassembled itself outside the chamber, first as a skeletal apparition, then a partial humanoid, then the fully blue-skinned omnipotent figure he becomes. Manhattan exists outside linear time; he experiences past, present, and future simultaneously. He has been the U.S. government's strategic deterrent for decades. The Soviet Union's military escalation has forced his recent withdrawal from Earth to Mars, where he sits alone in a self-built crystal palace contemplating the structure of fate.

The investigation into Blake's murder accelerates. Rorschach is framed for a separate murder and incarcerated in a maximum-security prison populated by criminals he himself put there. Nite Owl and Silk Spectre, having begun a romantic relationship after both abandoning their respective stagnant lives, break Rorschach out of prison in a costumed assault. Their action triggers a cascade. The Keene Act's enforcement collapses. Public protests demand the costumed vigilantes' renewed surveillance and arrest. The trio of Rorschach, Nite Owl, and Silk Spectre track the murders to the elaborate Antarctic complex of Adrian Veidt, the supposedly retired and publicly civilian-corporate Ozymandias.

Veidt has been the murderer all along. His larger plan, executed across years of preparation, has been to fake an alien interdimensional invasion of New York City using a synthetic creature he has created from genetic research and dimensional-physics experimentation. The fake creature will be teleported into Manhattan with a built-in detonation pulse that will instantly kill three million people. Veidt's calculation: the United States and the Soviet Union, presented with a common interdimensional enemy, will set aside their nuclear hostilities and unite the human species against the fake threat, preventing what Veidt has calculated to be an inevitable nuclear apocalypse within months. Three million deaths in service of saving five billion. Veidt has murdered the Comedian, Rorschach, and any other vigilante who came close to discovering the plan.

The detonation occurs while Veidt is monologuing his philosophy to Nite Owl, Silk Spectre, and Rorschach in his Antarctic command center. The film cuts to Manhattan's destruction: three million people are vaporized in an instant of unimaginable violence. Doctor Manhattan, on Mars, sees the event and teleports back to Earth alongside Silk Spectre, who has been visiting him to plead Earth's continued worth as a species. The team, gathered together in the Antarctic complex, learns of the global political response: the Soviet premier and the U.S. President have indeed announced a joint defense initiative. Veidt's calculation has succeeded. The world appears to be united.

The remaining Watchmen face an impossible moral choice. Telling the truth about Veidt's deception would destroy the new peace and probably trigger the nuclear apocalypse he has been preventing. Concealing the truth means living with the knowledge of three million murders permanently silenced. Doctor Manhattan, Nite Owl, and Silk Spectre choose silence. Rorschach refuses. He demands the truth be told regardless of the consequences. He walks out of the complex into the Antarctic ice. Doctor Manhattan, in a moment of grim mercy, vaporizes Rorschach with his powers to prevent him from carrying his journal back to civilization. Manhattan then leaves Earth permanently, having decided that human existence is fundamentally beyond his reach.

The film closes on the Daily News editor's office in Manhattan a few weeks later. Rorschach's mailed journal, sent to a small alternative newspaper before he traveled to Antarctica, has arrived in a slush-pile box of unread submissions. A bored intern, looking for column-filler material, picks up the journal and begins to read. The film cuts to credits. The implication is that Veidt's perfect crime may yet be exposed by the publication of Rorschach's words; the global peace he engineered may yet collapse; the moral question of whether his calculation was correct remains unresolved. Watchmen grossed $185 million globally on a $130 million budget, a financial disappointment compared to its production cost but a critical and cult success that established Zack Snyder as a commercially viable adapter of complex genre material.

Snyder's faithful page-to-screen adaptation translated Dave Gibbons's panel compositions into nearly identical cinematic framing in many sequences. The film's runtime, structure, and willingness to commit to the source material's bleak ending all reflected Snyder's commitment to fidelity. The film's most controversial change involved Veidt's alien-invasion device: in the graphic novel, Veidt fakes an actual extra-dimensional squid creature, while the film replaces this with an energy-pulse signature designed to frame Doctor Manhattan as the destroyer. The change streamlined the third act for film audiences but disappointed some long-time fans of the source material. The film's needle-drop soundtrack, featuring tracks by Bob Dylan, Simon & Garfunkel, and Jimi Hendrix, became one of its most-praised individual elements. HBO's 2019 limited-series sequel Watchmen extended the story into a different era and continuity, but the 2009 film remains the only theatrical adaptation of the original graphic novel.

Alan Moore, the original graphic novel's writer, has consistently disowned every adaptation of his work and refused screen credit on the 2009 picture; co-creator Dave Gibbons, however, supported the project publicly and visited the set during production. Moore's stated objection was philosophical: he believed Watchmen was specifically designed to demonstrate what comics could do that films could not, and that any adaptation would necessarily fail to capture the medium-specific qualities of the original. Snyder's response was that fidelity to the panel-by-panel composition was his way of honoring Moore's intent regardless of medium. The film's 2009 release coincided with the early phase of the Marvel Cinematic Universe's launch, and its commercial underperformance against superhero genre conventions was partially attributed to its failure to match the optimistic-team-up tone audiences had begun to expect.