Season synopsis
Contains spoilers for this season and earlier seasons.
Michael enters Sona, a Panamanian prison where inmates control daily life and settle disputes in a lethal fighting ring. The Company holds Lincoln's son L.J. and Sara and offers their release only if Michael breaks out James Whistler, an inmate wanted for killing a local official's son. Lincoln works from outside with Company operative Gretchen Morgan, while Sofia Lugo becomes involved through Whistler. Inside, Michael studies the prison's power structure, recruits help from young inmate Luis McGrady and uses Lechero's rivalries to build an escape route through a damaged underground corridor.
Whistler's identity and the Company's shifting demands make the plan hard to trust. Michael also keeps asking for proof that Sara is alive. Gretchen sends Lincoln a package containing what appears to be Sara's severed head; Lincoln initially hides it, then tells Michael that Sara has been killed. Michael believes him and turns on Whistler, but L.J.'s continued captivity and the escape timetable keep the men bound to the same dangerous plan. Mahone, Bellick and T-Bag each maneuver for a place in it as Sammy challenges Lechero’s control; Michael kills Sammy by sabotaging the tunnel’s supports.
Heavy rain threatens the tunnel, forcing Michael to bring the breakout forward. Lincoln cuts Sona's power to give the men cover. Lechero is shot, but Michael, Whistler, Mahone and McGrady reach the beach and escape with help from McGrady's father; Sucre is left behind and exposed as an accomplice. The brothers trade Whistler for L.J. in a museum, where Sofia learns Whistler works for the Company and chooses Lincoln. Gretchen escapes the police, Michael sets out to find and kill her, and T-Bag takes control inside Sona.