Veronica Donovan (played by Robin Tunney; seasons 1-2) is a real-estate lawyer and a longtime friend of the protagonists of the series, who unsuccessfully tries to find evidence to exonerate Lincoln Burrows.

The original security tape which they were looking for is destroyed and in the subsequent episode, "Riots, Drills and the Devil Part 2", they are threatened via a public phone call in Washington, D.C. and are targeted by Paul Kellerman and Daniel Hale, who are members of the conspiracy.

However, at the end of the episode "Tonight", Veronica is betrayed by Nick, who turned out to have made a deal with John Abruzzi to have her "ready and waiting" at the airport on the night of the escape in exchange for his father's freedom.

Fernando Sucre (played by Amaury Nolasco) is imprisoned at Fox River State Penitentiary for aggravated robbery and was ratted out by the man trying to steal his girlfriend.

is targeted by conspiracy agents Paul Kellerman and Daniel Hale; after they frame him for the murders of his mother and stepfather, L. J. flees to Veronica Donovan and Nick Savrinn’s secret cabin.

Bradley Bellick (played by Wade Williams; seasons 1-4) is the main prison guard in the Fox River State Penitentiary correctional officers but is later dismissed.

Theodore "T-Bag" Bagwell (played by Robert Knepper) is imprisoned at Fox River State Penitentiary with a life sentence[2] for six accounts of kidnapping, rape, and murder.

Though Bagwell initially believed himself to be incapable of fathering a child due to being conceived as a result of inbreeding, Michael reveals to him that he has an illegitimate son in David "Whip" Martin.

When Whip is killed, T-Bag snaps the neck of his killer; and as a result finds himself imprisoned in Fox River; where he exacts further vengeance upon Poseidon, who is assigned his cellmate.

Another factor which contributed to her occupational choice was her past morphine addiction, culminating in being unable to help a boy after he was run over, because she was high, which was revealed in a flashback episode of the first season, "Brother's Keeper".

Alexander Mahone (played by William Fichtner; seasons 2-4) is an FBI Special Agent, who is put in charge of the nationwide manhunt for the Fox River escapees.

Susan aka Gretchen tells him the plan Bang and Burn is in effect, which both dismissed as suicide until Pad Man says it is the only option after Michael failed to take James out of Sona.

[6] Gretchen provides assistance to both of the brothers so that their plan would work, such as money for the gravedigger (whom she eventually executed as she suspected that he might report them to the police)[6] and a drug that could help silence a guard.

When the escape ultimately fails, Gretchen's supervisor, General Krantz, forced her to carry out the "Bang and Burn" Operation, which involved flying helicopters into Sona to retrieve Whistler.

Gretchen and T-Bag serve mainly as wild cards in these episodes, playing Michael's team, with their real plan revealed to be using them to get Scylla, only to then steal it and sell it to a Chinese crime syndicate for 125 million.

In their scenes together, Gretchen is often the more ruthless character, while T-Bag appears more hesitant as he grows attached to salesman Cole Pfeiffer, the alias he is living under to facilitate the break-in.

"[15] Taking Mahone's advice; to get aggressive, Self meets the General face-to-face and blackmails him, threatening to reveal to the public missions he was involved in, thus making it harder for The Company to remain covert.

Realizing that the needs to find a new buyer after the first one is killed, Self murders his partner, federal agent Miriam Holtz, in cold blood in order to get to T-Bag, a prisoner she was guarding.

Self's character plays a less prominent role in the season's final episodes, where he works with his new team to find Scylla and track down the new buyer, which turns out to be Lincoln and Michael's mother, Christina Rose Scofield.

When the team fails in their assignment, the general decides to punish them by ordering the death of one of their family members and singles out Self's wife, who is actually alive and in a persistent vegetative state due to Self's drunk and reckless behavior.

In the season premiere, he is shot in the leg by someone supposedly sent to kill Sara and Mike due to Lincoln investigating Michael's death, and spends the next two episodes recovering in the hospital.

During this time, it is revealed that his real name is David Martin, and that he was a survivor in prison, which is why Michael chose him as his partner (and the cover story he told Ramal may have been why he was originally incarcerated).

As the season unfolds, Michael and his team eventually learn of the General's identity and his place as the leader of The Company, and he gradually comes to the forefront of the plot with increased screen time with the protagonists as a consequence.

The last third of the fourth season shows the General trying to use leverage to control and motivate Lincoln and his team in their pursuit of Scylla, while instructing his men to kill Michael, who escapes from Company security after the surgery.

It is revealed in the series epilogue set four years after the events of the finale that Krantz was tried (possibly for treason and multiple counts of murder) and sentenced to death via the electric chair.

As the character's role grows bigger, he becomes the primary antagonist of the brothers in season 2, and Kim begins to share screen time with them, most notably in "Sweet Caroline" where he violently attacks Michael in an attempt to make him reveal Lincoln's whereabouts.

Her appearances in "The Mother Lode" and "VS" are devoted towards setting the stage for her grand master plan, as she meets with the son of the Prime Minister of India to offer him Scylla technology.

At the end of the episode, the real nature of her plan is revealed to be the assassination of the Prime Minister's son and shifting blame onto the Chinese, thereby provoking a war between India and China that she will profit from by selling Scylla weaponry data to both sides.

As the two continue to uncover the conspiracy In "Riots, Drills and the Devil (Part 2)", they are threatened via a public phone call in Washington, D.C. when they find the old offices of Ecofield, Terrence Steadman's company.

Michael finally cuts him out of the mission in the next episode "The Price", causing Roland to take on the role of antagonist by double-crossing the team, offering Scofield and Burrows’ location to Wyatt for 1 million dollars.