The vast societal issue of mental health and suicidal thoughts are portrayed with such genuine cinematic realism in Kim Ui-seok's somber debut that we are inescapably immersed in those dark topics.

Indeed, for some viewers the film might be overtly provoking on these issues, but what it cannot be accused of is providing a sanitised version of the horrors of suicidal considerations.

Any viewer will need to be in the right place to withstand the relentless onslaught of dark thoughts, bleak acts and tragic turns.

The film is overtly emotionally consuming, but in among the various shades of grey is a fine demonstration of the power of cinema – so real are the issues on screen, it makes you want to reach out to anyone you might suspect of harbouring similar thoughts. If the film musters one real-life intervention on such issues, its dim palette would have been justified.

Kyung-min (Jeon So-nee), a schoolgirl considered somewhat of an outsider (“She doesn’t listen to K-Pop") goes missing. With her bag and shoes found on a bridge, she is suspected of committing suicide.

The police start to trawl the river for her body and question her classmates, including Young-hee (Jeon Yeo-been), the last person to be seen with Kyung-min, who becomes the focus of police suspicion, the wrath of Kyung-min's mother (Seo Young-hwa), and the chagrin of her other classmates.

As all parties descend on Young-hee, her own mental health deteriorates and she starts to look for her own answers for why Kyung-min might have committed the tragic act. We start to unpack a fuller account of what caused Kyung-min's disappearance and are taught a lesson in the impact of the lust to find an instant scapegoat.

While the seeming focus should be on what could have caused Kyung-min to do this, we also get a demonstration in the blame game and self-preservation that others perform in such situations. Kyung-min's parents turn on each other, the school heads are keen to distance themselves from liability, and her classmates spiral into a perpetual finger-pointing routine.

Kim Ui-seok's approach is what gives the film its brutal and ice-veined power. There are no exaggerated characters or situations here. It is us sharing time with deeply emotionally damaged souls and their attempts to piece a life together. Having previously worked with Na Hong-jin (The Chaser, The Yellow Sea, The Wailing), that ability to portray emotional tension seems to have been transferred.

The result is a hard-to-watch film where we are glued to every single tragic moment. “Isn’t it a relief that all this will be over one day,” one character rhetorically ponders. There are moments when you wish this film will be over, yet will be thinking about it weeks later. The tragedy of suicide embalmed in the power of cinematic realism.