This is a gripping, brutal and at times hypnotic film that looks deep into the minds of people who act on a compulsion to kill.

While exploring these dark places it also manages to introduce a bit of shade through visual flair and a touch of self-parody that takes some of the sharpest edges off a series of inventive and violent action set-pieces.

It’s not a film for the faint-hearted, but it is terrifically shot and edited and in equal parts fascinating and unsettling in its approach to difficult material.

The directors are the Mo Brothers, also known as Kimo Stamboel and Timo Tjahjanto, who were previously responsible for Macabre in 2009 and Headshot in 2016. Producers and stars of The Raid 1 and 2 are also involved, creating a formidable creative team.

For the first part of the film, the action is split between Tokyo and Jakarta. The harrowing initial sequence introduces us to a wealthy young Japanese businessman who is also a sadistic serial killer and cannibal. He tortures and murders his female victims on camera and then edits the film into a short package that he posts on-line.

Nomura, as played extremely well by Kazuki Kitamura (Kill Bill 1 and 2, The Raid 2), is a cold, calculating psychopath who initially appears to have no redeeming attributes. As the film progresses, the confusing actions of the character cause our reactions to also vary wildly. At one stage he appears to be seeking to help a woman and her younger brother get their lives back on track; only to later divulge far more sinister motives.

Early in the film we are also introduced to an even more complex character in Bayu, again played strongly by Oka Antara (The Raid 2). Bayu is a freelance journalist who has just seen the corrupt businessman he tried over many years to expose, walk free. Bayu continues to be consumed by the businessman, Dharma, with his psychosis further impacted by the break-up of his marriage.

Bayu happens across one of Nomura’s on-line videos around the same time that he is unintentionally involved in a violent incident himself…a worthy rival to the great taxi scene in Korean horror I Saw the Devil.

The two men eventually make online contact with their interactions slowly intensifying to the point where Bayu gives extreme vent to his own vengeful intentions.

This progression will be a leap too far for some viewers who may be turned off by the underlying logic and character motivations…not to mention the extreme violence.

But it also makes for an intense experience if you just play along and enjoy the darkness it revels in. This is particularly the case for the final act which, as you would expect, brings the two killers together for an inevitable psychological and physical showdown.