[s12e18]: Hell's Kitchen

He continues his complicated relationship with fellow inmate Calvin Shaw.

He uses a specialized "blood-letting" kit and keeps victims in a hidden basement cellar. [S12E18] Hell's Kitchen

The Unsub, John Pringle, is a "blood drinker" who suffers from a delusional belief that consuming the blood of young, healthy victims will cure his own terminal illness. He continues his complicated relationship with fellow inmate

Dr. Spencer Reid's ongoing incarceration and legal battle. Case File: The Unsub [S12E18] Hell's Kitchen

Reid is struggling to survive the harsh environment of the correctional facility.

A major focus of this episode is time in prison.