After the helicopter fails to break out Whistler, Sona's new commander, General Zavala, decides to make Michael talk by putting him into a sun-exposed isolation hot-box. He promises to help in exchange for the truth, verifies the L.J. situation and is told it's about Whistler. Whistler, realizing the tunnel is a no-go without engineer Scofield, denies knowledge blatantly to Zavala and is threatened with torture, until he admits to collaborating with Michael, who convinces him to give up Susan/Gretchen's name. Meanwhile Lincoln, is given a short meet up with L.J. as motivation.
Mahone is back in Sona, desperate without his drug. T-Bag and his allies are mainly concerned with Lechero's expected succession and another bare-knuckle fight, won by Bellick. Gretchen recruits Sucre as a double spy (or triple for Linc); then General Zavala arrests and tortures her. Only Whistler's admission makes her admit L.J.'s kidnapping and leads them there, but she manages to kill the General and escape. Michael and Whistler are returned to general population, Mahone and T-Bag join the tunnel escape party. Lechero's cousin Augusto, now calls on Sammy to open the package - a gun.