THE WHITE HOUSE VOWS NEVER AGAIN, WHILE THOMAS PLANS HIS ENCORE—ROGER BART AND GABRIELLE CARTERIS GUEST STAR— Still reeling from the attack in Alaska, President Martinez (Blair Underwood) reasserts control over the situation and his administration, counseled by Sterling (Zeljko Ivanek) and his Chief of Staff (guest star Roger Bart, “Desperate Housewives”). Sophia (Laura Innes) learns the details of Thomas's murderous rampage. Thomas (Clifton Collins, Jr.) sets Sophia and Martinez further at odds. Elsewhere, Michael (Scott Patterson) leaves Leila (Sarah Roemer) in safekeeping with a close friend, Diane Geller (guest star Gabrielle Carteris, “Beverly Hills, 90210”), while he goes on the hunt for Thomas. The NSA continues to decrypt the satellite transmission, hopefully before it's too late. Ian Anthony Dale, Bill Smitrovich, Taylor Cole, and Lisa Vidal also star.