This Level is the main Level for every inmate of the Prison. Only the most violent are send to Level Two.
This level was never made public due it was used to do with the more violent inmates those who relapsed to their more violent nature. They received treatment from Jarrett Parker. When Oliver Queen and Talia al Ghul managed to expose the truth about Level Two, the Level was closed down and all inmates being held there were send back to Level One.
- B. Dunbar (guard; deceased)
- Jarrett Parker (chief psychiatrist; deceased)
- Peter Yorke (guard; fired)
- Talia al Ghul (escaped)
- Danny Brickwell (deceased)
- Ricardo Diaz (deceased)
- "Grim Reaper" (deceased)
- Oliver Queen (released)
- Derek Sampson (deceased)
- Ben Turner (released on parole)
Behind the scenes
- In the DC comics, Slabside Penitentiary or the Slab, is a meta-human prison run by Shilo Norman/Mister Miracle.