PA: Due to some graphic content, viewer discretion is advised.

VERONICA AND NICK GET AN EXPLOSIVE WARNING; A PART OF MICHAEL'S PLAN IS MORE GUARDED THAN HE THOUGHT; BELLICK IS DETERMINED TO FIND A KILLER; LJ GOES ON THE LAM; THE CONSPIRACY CLAIMS THREE MORE LIVES; AND THE MYSTERY WOMAN'S IDENTITY IS REVEALED ON 'PRISON BREAK,' MONDAY, OCTOBER 24 ON FOX

Michael's plan hits a snag when he discovers an old storage shed crucial to the escape has been turned into the guard's break room. Veronica and Nick get an explosive warning to back off their investigation to prove Lincoln's innocence; LJ goes on the run; the conspiracy claims three more lives; the identity of the mystery woman calling the shots is revealed on "The Old Head" episode of PRISON BREAK airing Monday, October 24 (9:00-10:00 PM ET/PT) on FOX. (PB-108) (TV-14 D, L, V)

Cast: Dominic Purcell as Lincoln Burrows; Wentworth Miller as Michael Scofield; Robin Tunney as Veronica Donovan; Amaury Nolasco as Fernando Sucre; Sarah Wayne Callies as Dr. Sara Tancredi; Stacy Keach as Warden Henry Pope; Peter Stormare as John Abruzzi; Wade Williams as Officer Brad Bellick; Paul Adelstein as Special Agent Paul Kellerman; Robert Knepper as T-Bag; Marshall Allman as LJ Burrows

Guest Cast: Jessalyn Gilsig as Lisa; Frank Grillo as Nick Sarvinn; Danny McCarthy as Special Agent Danny Hale; Muse Watson as Westmoreland;