Coherence, in Five Parts
An original condensed retelling of James Ward Byrkit's 2013 film
Part 1: A Dinner Party, and a Cracked Phone
On the night a rare comet is passing close to Earth, Em drives to a dinner party at her friends Mike and Lee's house, chatting on the phone with her boyfriend Kevin about an unresolved issue between them. The call abruptly drops, and inexplicably, her phone screen cracks on its own, an unsettling first sign of a strange night ahead.
At the gathering, Em joins a small group of close friends, including Mike, Lee, Hugh, Amir, and Beth. Tension enters the room almost immediately when Amir arrives with an unexpected plus-one: Laurie, Kevin's ex-girlfriend, adding an awkward undercurrent to what was meant to be a relaxed evening among friends.
As the group settles in, conversation turns to the passing comet and its strange historical associations, including an unsettling story Em recalls about a woman in 1923 Finland who called the police convinced the man in her house was not actually her husband, a detail that plants the film's central unease well before anything overtly strange actually happens.
Part 2: The Lights Go Out
One by one, the guests realize their phones have lost signal entirely, and the house's internet connection has gone down as well, with the group only half-jokingly attributing the disruption to the comet passing overhead. Before they can make much sense of it, the power in the house cuts out completely, plunging the party into darkness.
Searching the basement for supplies, Mike finds three unopened boxes of glowsticks, each containing a different color, blue, red, and green, a seemingly minor detail that will soon become critical to the group's survival. They open the blue box and head outside together to watch the comet pass overhead.
Noticing a single lit house glowing down the street, seemingly the only other home with working power in the entire dark neighborhood, a small group decides to investigate, hoping to find help, a decision that instead pulls them directly into the film's central, reality-bending nightmare.
Part 3: A House Just Like Their Own
The investigating group returns with deeply unsettling news: the other house is identical to the one they just left, right down to the layout and the people inside, who appear to be exact duplicates of themselves, still mid-party, unaware anything is wrong.
Hugh, the group's resident science-minded voice, offers a framework for what might be happening, invoking quantum decoherence and the classic thought experiment of Schrödinger's cat, explaining that two contradictory realities can technically coexist until the moment they're directly observed, at which point they collapse into just one. He suggests the comet has somehow disrupted that natural separation, allowing multiple nearly identical realities to cross into each other for one night only.
Terrified and increasingly paranoid, the friends begin using the colored glowsticks specifically to mark which version of reality, and which version of each other, they're currently dealing with, since the various duplicate selves loose in the neighborhood look and behave almost identically to the originals, differing only in small, easily missed details.
Part 4: Crossed Wires
As the night stretches on, more and more members of the group unknowingly slip between different versions of the house and the party, encountering other-universe copies of their friends, and sometimes of themselves, without fully realizing which reality they've actually landed in at any given moment.
Suspicion, jealousy, and old unresolved tensions, particularly between Em, Kevin, and Kevin's ex Laurie, boil over as the chaos deepens, with characters increasingly unsure whether they're speaking to their actual friends or subtly different duplicates from another branching reality entirely.
The group attempts to establish rules to manage the crisis, marking safe zones and insisting no one go outside without a glowstick to track which reality they belong to, but the growing panic and shifting loyalties make it increasingly difficult to trust that anyone, including oneself, is really where or who they're supposed to be.
Part 5: Which Emily Are You
Em ultimately becomes fixated on one particular alternate reality: a version where her relationship with Kevin appears far happier and more resolved than her own troubled one. Determined to claim that better life for herself, she confronts, subdues, and effectively takes the place of that version of Em, physically overpowering her counterpart to seize the more desirable reality.
Waking up afterward, Em believes she's successfully settled into the "perfect" version of her life, reunited with a Kevin who seems genuinely happy and unaware anything is amiss. For a brief moment, her gamble appears to have paid off entirely.
Then her phone rings. On the other end is another Em, one of what the film's ending strongly implies could be countless alternate versions of herself, all having lived through the exact same night, all potentially making the exact same desperate choice to hunt down a better version of their own life. The film cuts to black on that unresolved, unsettling note, leaving open the possibility that Em has traded one uncertain reality for another, with no true, final escape from the chaos the comet unleashed.
This piece is an original condensed adaptation summarizing the plot of James Ward Byrkit's Coherence, written for general audiences and not a reproduction of the original film.
Still Struggling to uinderstand Coherence? Use This Cheat Sheet
A dinner-party movie shot in the director's actual house, with a cast that had no idea how the story would end while they were filming it. Here's what you need to know.
Q: What's it actually about, in one sentence?
Eight friends gathered for a dinner party on the night a rare comet passes overhead gradually realize the event has caused multiple nearly identical realities to overlap, and as duplicate versions of themselves and their homes start crossing into one another, the group descends into paranoia over which version of reality, and which version of each other, they're actually dealing with.
Q: Was this a hit when it came out, or did it flop?
It was a tiny production that built an outsized reputation. Director James Ward Byrkit, previously a storyboard artist on films like Pirates of the Caribbean and Rango, shot it over just five nights in his own house, and it went on to earn a strong cult following, frequently name-checked alongside Primer as one of the standout examples of ultra-low-budget, high-concept science fiction.
Q: So why does everyone still bring this film up today?
Because of how it was actually made: there was no traditional full script, with actors given only outlines of each scene and, in several cases, deliberately kept unaware of major plot developments so their reactions on camera would be genuinely spontaneous rather than performed. It's also frequently cited as having arrived well ahead of the current wave of mainstream multiverse films, predating movies like Everything Everywhere All at Once by nearly a decade using a fraction of the budget.
Q: What's the one line people quote from this?
Explaining the science underpinning the entire premise, Hugh describes quantum decoherence using the classic thought experiment of Schrödinger's cat, summarizing it as, "It's only when you open the box that they collapse into a single event," the closest thing the film has to a thesis statement for its entire premise of overlapping, colliding realities.
Q: Is this really just a sci-fi gimmick movie, or is there a deeper meaning?
The title itself is a pointed irony: "coherence" is the opposite of the actual scientific phenomenon driving the plot, quantum decoherence, which is what normally keeps separate realities from ever interacting at all. Underneath its science-fiction premise, the film is really an unusually literal way of asking a familiar question, whether the grass is truly greener elsewhere, by having its lead character discover an ostensibly "better" version of her own life and having to decide just how far she's willing to go to claim it.
Q: Why do people find this one hard to follow, despite its acclaim?
Multiple nearly identical versions of the same characters cross paths throughout the film with only small, easily missed differences distinguishing them, and the group's own glowstick-based system for tracking which reality is which requires close viewer attention to follow accurately. Critics and fans alike generally agree this is a film that rewards, and sometimes requires, a second viewing to fully track who's who by the end.
Q: What's a high-value, low-effort trivia fact I can drop about this?
The cast were reportedly not given a traditional script at all, working instead from a loose outline of events for each scene, and several major twists were kept hidden from the actors themselves during filming specifically so their shocked, confused reactions on screen would be completely genuine rather than acted.
Q: What context actually unlocks the rest of this film?
Know the mechanic going in: the comet has caused the normally impossible phenomenon of quantum decoherence to reverse, allowing multiple parallel versions of the same night, and the same people, to physically overlap for a few hours before separating again permanently. Tracking which colored glowstick, and therefore which reality, each character is currently holding is the single most useful trick for following the plot on a first watch.
Q: Got a second quote I can use — something from criticism rather than the film?
One widely shared assessment ranks the film as being "up there with Primer as two of the greatest mindjob movies" made in the low-budget science fiction space, a useful comparison to drop since it immediately places Coherence alongside another famously complex, well-regarded indie sci-fi puzzle film.
Q: Cheat sheet vs. actually experiencing it — what's the honest verdict?
Absolutely worth watching, and this is a film whose disorienting, paranoid tension depends entirely on experiencing the escalating confusion in real time alongside the characters, an effect a plot summary simply cannot replicate. Given how much the film rewards close attention to small details, it's also one of the better candidates on this whole list for an immediate rewatch right after finishing it.
This piece paraphrases and contextualizes publicly documented plot details and criticism about Coherence; direct quotations are limited to one line from the film itself and one line from published critical commentary comparing it to Primer.