All roads lead to solitary, and a season finale of cliffhangers commences as:

Hill returns from Benchley Memorial, to his own private room in the hospital. He refuses to tell McManus who gave him the drugs, but says it wasn't Urbano. Tim tells Redding, who confronts "witness" Busmalis. Busmalis and Poet lie that Guerra was responsible. This leads to a brawl between Redding/Morales and their respective groups.

The inmate variety show takes shape with Father Mukada as MC and White the featured performer, and with Omar White as the finale. Said returns from the hole ready to apologize to White, and the two turn over a new leaf in their relationship. Robson's painful teeth force him to the dentist, something he secretly fears. The dentist recommends gum replacement surgery. Alvarez wants to give his dog to Eugene Rivera (the Oz guard he blinded). Cyril's trial looms and gets off to an inauspiciously cold start. Ryan is worried and cuts a deal that gets Shupe disabled. Redding continues to search for culprit that gave Hill the drugs. Poet, in an attempt to hide the truth from Redding convinces Busmalis to tell Redding that one of the Italians did the deed. This results in Redding having DeSantos poisoned. Chucky's condition worsens and out of fear, he summons Sister Peter for spiritual help. Dr. Nathan counsels Peter Schibetta. Sister Pete starts looking for Schibetta's attackers only the 3 who know (Said, Beecher, Schillinger) refuse to divulge. tensions between Mukada and Kirk come to a boil when Mukada convinces Hoyt to squeal. In exchange for a blow job, Timmy Kirk has Clarence get someone to burn down Father Mukada's church and rectory. He is seriously injured, and two other priests die. Beecher and Keller anger McClain, who walks out. Howell gives Keller a free trip to Benchley Memorial. Beecher takes Schillinger's deal: He takes the mail job and Adam is transferred to Unit B.

Said and Arif go to Warden Glynn about Lalar's murder. Angry and full of rage, Said then confronts White about passing drugs. Unsatisfied with White's response, Said beats White severely, which gets Said thrown in the hole. Robson stirs up trouble. Pancamo develops a staph infection. On orders from Schillinger, Winthrop gets into a fight with Guenzel. Schillinger goes to Beecher to win favor only he intends to have Beecher turn Guenzel over to him to be his "slave". Guenzel doesn't want to be seen with Beecher the 'faggot'. Keller discovers the feds have compelling evidence linking him to one of the past murders. Meanwhile, Howell makes her move on Keller. Officer Brass makes off with Rebadow's winning $2 million lottery ticket.

Velez fails in his attempt to kill Guerra. Miss Sally's Schoolyard is cancelled, and replaced with Sallycize. Schillinger threatens Schibetta. The O'Reily brothers band together to protect Suzanne. Gloria attacks Martinez when he gropes her while she's treating him in solitary. The Aryans attack Lalar. Hill can't stop thinking about his mother's death.

Redding and Morales forge an uneasy defensive alliance; Keller returns; the Cloutien mysters deepens.

Suzanne Fitzgerald begins community service teaching music in Oz. Montgomery threatens to expose Ryan's scheming, but Ryan schemes his way out free of Montgemoery. McManus gives Said a new project, Omar. The hitman that killed Hank gives up Pancamo, and Schillinger takes revenge. The Reverend Clutier continues to influence his followers beyond his infirmary bed.

Oz re-opens after the renovations. Complications leave the Solitary inmates in Gen Pop for a while. Ryan does what he does best, complicating the investigation into Keenan's murder. Beecher, Said and Schillinger agree to interaction sessions. A busload of visitors to Oz skids off the road and many are killed before seeing their loved ones.