Now locked up in a Panamanian prison known as Sona, Michael, T-Bag, Bellick, and Mahone try to find a way out. Much to their devastation, they soon find out that the prison has been abandoned by the authorities because of the immense threat from the vile inmates. Michael seeks for an inmate named Whistler in the prison sewers. As Lincoln is puzzled by Sara's sudden disappearance, he learns that LJ has gotten into some trouble. He also tries to recover the 5 million dollars.

Michael and Mahone try to lure Whistler out of his hiding place. T-Bag gains some upward momentum in the prison hierarchy as the water supply is running low. Lincoln meets familiar and not so familiar faces on his quest to free Michael.

Susan jeopardizes Michael's life as she puts her own escape plan into motion. Whistler's past catches up to his girlfriend.The Company goes after Lincoln and Sucre. Justice prevails for Mahone. And Lechero sheds light into an empty tunnel.