Interference is the fifth episode in Season 3.
Linc visits Michael; the escape deadline is tomorrow. Linc needs to arrange a getaway vehicle for 3pm - the only way to avoid the military jeeps is to be able to see them, so they need to escape in broad daylight.
A new inmate, Andrew Tyge, sees Michael and Whistler talking. He recognizes one of them. Michael asks McGrady for a watch and binoculars. Michael outlines his escape plan to Whistler; but first, he needs to get to know the guards better to find out their weaknesses. Whistler's cell overlooks the other guard's tower; Michael asks him to observe him all day, and gives him one half of the binoculars.
An impatient Susan is looking at a blueprint of a large building and labeling it with numbered post-its - steps in a plan?
Whistler finds that there's a time of day when there's a blind spot for the guard for six minutes. Michael has found that the other guard occasionally adjusts his TV when there's interference - and he can build a transmitter to help jam his signal. Tyge is spying; Michael almost catches him, but not quite. However, Mahone has seen Tyge, and tells him to mind his own business.
Lincoln and Sofia try to take an off-road, but it's a private government road and they're stopped and bullied by the police, though Sofia talks them out of any trouble. The officer says he'll remember Lincoln, though.
As T-Bag continues to provide Mahone with drugs, Sammy picks up the package that Sucre has smuggled in. Michael steals the microwave of a particularly tough inmate. He uses it to finish his jamming device. It works - but the guard suddenly takes aim at Michael's cell and sprays the window with bullets. An alarm blares. Colonel Escamilla and his men enter the prison - a guard reported seeing a rifle scope, and he's not leaving until he finds the rifle. Sister Mary Francis mustn't be found by the soldiers; T-Bag hides her and promises to keep her safe. He seems to have a genuine affection for her.
The monoscope is found in Michael's cell. The guard, Hurtado, demands to know why Michael was watching him. Whistler steps up and says the scope is actually his, and he wasn't watching the guard, he was watching birds. He shows the bird book as proof that he's a birdwatcher. The General is mollified.
Lechero returns to his cell - to find that Mary tried to steal $30 from his unguarded cashbox. T-Bag steps up and claims he gave the money to her and planned to replace it by the end of the day. Lechero is angry, and roughs T-Bag up, but Mary is out of trouble for now.
Lincoln buys some supplies at a dive shop, and then goes with Sofia to the beach, not far from the prison gates, where he buries four small scuba tanks. A getaway for himself, Michael, Sofia and Whistler. International waters are 12 miles off the coast. Lincoln and Sofia start to trust each other.
Michael is locked out of his cell, all his belongings inside; his plans are ruined. But Mahone has noticed something else from his own cell - Hurtado has a coffee fix. They and Whistler run into Tyge - who is sure he knows Whistler. He calls him McFadden and says he was in Nice, in 1997, with the Ambassador. Whistler insists Tyge's insane, he's just a fisherman. Neither Michael nor Mahone believe him. But Mahone doesn't care - he just wants to get out.