officer darlene fieste is still adapting to working behind the walls of folsom. >> i'm not used to being around violence when i started, you know, not that. it really shocked me. how cruel and emotionless these people can be. >> it does get scary sometimes. you hear a lot of the war stories from around here. >> i've been stabbed. i've had my knee broke. >> i had a back injury first, stabbed. >> i was assaulted by an inmate in handcuffs. >> i was stabbed seven times. >> if you show the inmates fear, then they're going to go ahead and feed on it. >> keeping that fear in control can be difficult inside this 100-year-old prison because what was state of the art at the turn of a previous century is now the biggest challenge to the officers' safety. >>> when we return, cellblock 5, the most notorious cellblock inside folsom. man (sternly): seriously? where do you think you're going? mr. mucus: to work, with you. it's taco tuesday. man: you're not coming. i took mucinex to help get rid of my mucusy congestion. mr. mucus: oh, right then i'll swing by in like 4 hours... just set aside a few tacos