With only six hours left, the clock races toward the series finale as President Allison Taylor faces impossible choices and much to the dismay of CTU, she enlists a private security firm to complete a sensitive task led by Mark Bledsoe (guest star D.B. Sweeny). Meanwhile, Jack calls in a favor to his old friend Rick Vickers (guest star Michael Madsen) before he embarks upon a crucial mission of his own. Guest Cast: Gregory Itzin as President Logan; Bob Gunton as Ethan Kanin; Necar Zadegan as Dalia Hassan; Naneen Contractor as Kayla Hassan; James Liao as Devon Rosenthal; Reed Diamond as Jason Pillar; Michael Madsen as Jim Ricker; D.B. Sweeny as Mark Bledsoe; Navid Negahban as Jamot; Lesley Fera as Press Secretary; Justin Alston as Agent Beck; Graham McTavish as Mikhail Novakovich.9 p.m. Monday. Fox.