A young married couple, Jang Mung (Dou Shawn) and Bing Bing (Li Jing Yi), are spending the day enjoying each other's company in a beautiful Beijing park. Needing to use the toilet, Bing Bing heads off to a nearby public convenience, while her husband waits patiently for her on a park bench in the sun. When she fails to return after a few minutes, he understandably begins to worry and attempts to call her on her cellphone, but to no avail.
As his anxiety increases, he is interrupted by a stranger, Sung-gil (Seo Hyun-woo), who demands that he take a photo of him, but no sooner does he dismiss him out of hand than he could swear he hears Sung-gil mutter “Don’t you want to know where your wife is?”...

While A Moment is a fairly simple story, as a great many of the best stories are, there is far more to it than initially appears to be the case, with the perception of absolutely everything referenced, portrayed and visually shown changing (even inverting, in some cases) as the narrative progresses to slowly reveal the film’s true nature. Like much of Oh In-chun's other work (both previous and subsequent to A Moment), even the core narrative theme gradually morphs from detailing one cautionary tale to another:
Beginning as a seemingly straightforward thriller based around the idea that bad things sometimes happen to good people, A Moment gradually shows itself to in fact be a tale of revenge and retribution, in classic Korean cinema style, increasingly blurring the lines between guilty and innocent in the process. However, even in the earliest stages of the film, there are inklings of unthinking actions which, though easily dismissed in our day-to-day lives, are sometimes seen by others as far more significant, and thus the seeds of ideas that will become pivotal plot points at a later stage, are eloquently sown.
A Moment was a collaboration between the Korea National University of Arts and Beijing Film Academy, with the soundtrack in Chinese for the majority of the running time, switching to Korean in the latter stages, and this further reinforces the idea of things being different in reality (or from others' points of view) to what first impressions would lead us to assume, as well as allowing the overall film to move from simply being 'Asian' in feel to ultimately become specifically Korean in style as well as substance and language, as the storyline progresses.
Not only that, but the film's title of 'A Moment' also undergoes a gradual change in focus (altering in tandem with, and as a result of, changing viewer perceptions) - initially pointing to how lives in the present can be irrevocably altered in just a moment, to finally and boldly stating that it only takes a moment's action (or lack thereof) to call karma into play, be it sooner or later.

Finally on the subject of changing perceptions and the switching of focus within themes, even the main characters themselves undergo this process. Hindsight, they say (whoever "they" are), is 20:20 and A Moment resolutely proves that to be the case, for characters and viewers alike.
All in all, virtually every element of A Moment undergoes a transformation of sorts, or metamorphosis if you prefer.

To fit so many underlying ideas into a narrative that lasts just twenty minutes is, without question, an accomplishment in itself, but it is achieved so naturally and seemingly effortlessly in A Moment that it positively screams of a directorial talent standing head and shoulders above the majority of the competition - a talent that truly deserves to be recognised by both the Korean cinema industry and as large an audience as is humanly possible.

Obviously fictional though it is, the idea on which A Moment's storyline is based is fairly topical regardless of viewer nationality or, in fact, the year in which the film is viewed. However, a number of recent events that have taken place in China (widely reported around the world) serve to bring an extra level of realism to proceedings, to an almost uncomfortable extent, and add a poignancy that is so clear as to be almost heartbreaking. I do realise that I'm being rather vague as to the specifics of those news stories, but in detailing them further I would risk spoiling the unexpectedness of A Moment's ultimate message. In short, a well known saying sums up this cautionary tale to a tee:  "There, but for the grace of God, go I".