Based on a true Hong Kong story, "With Prisoners" is set in a detention center for offenders aged 14 to 24. Inmates are subjected to daily physical and mental abuse.
Young gang leader Fan is jailed for a minor conflict with a police officer and attempts to kill himself on the third day of his detention due to the staff's cruel treatment. Fan is rescued from his suicide attempt, and decides to endure his incarceration in order to visit his ill grandmother upon release. Throughout the rest of his detention, he witnesses and experiences insults from the staff, as well as the mysterious death of an inmate, while the truth is likely to remain unknown to the outside world.