I have been meaning to watch this for a while, finally got to see it on Apple TV.
A true story, of Billy Moore, an Englishman who ends up in a violent Thai jail where a long standing Heroin addiction is not helped by an active drug trade. The prison is an overload on the senses - with extreme violence, gangs, rape and torture.
Gradually Billy finds his way to the gym in the prison where he builds up some esteem and conquers his demons by finding focus in Muy Thai boxing.
Joe Cole is superb in this, playing a bewildered addict in a foreign place brilliantly, in the next moment he can be vicious and extremely violent. The remaining cast are Thai, with very little English spoken.
The film was made in a Thai prison, and the dialogue appears to be deliberately without subtitles to increase the feeling of alienation. The sound design is intense, and scenes are filmed hand held and close up.
The boxing scenes are furious and realistic. The violence comes frequently and seems fitting for the setting.
I highly recommend this, but warn against the assault of every sense you'll feel.