S1, E12: President Martinez (Blair Underwood) and his longtime Chief of Staff (guest star Roger Bart, "Desperate Housewives") charge the intelligence community with decrypting Thomas's (Clifton Collins, Jr.) satellite message, but more importantly determining to whom it was sent. While they are distracted, Thomas unveils a surprise attack, but he does not anticipate a heroic stand-off with Blake Sterling (Zeljko Ivanek), who learns an important lesson about Sleepers from Maya (guest star Clea DuVall, "Conviction"). Meanwhile, newly appointed Alaskan Senator Catherine Lewis (guest star Virginia Madsen, "Sideways") threatens to divulge information about the Mt. Inostranka detention facility on an episode of "HARDBALL with Chris Matthews" . Elsewhere, Sean (Jason Ritter) and Leila (Sarah Roemer) get a fresh lead on the whereabouts of Samantha, but it leads them to a dramatic turn in their lives. James Dempsey (guest star Hal Holbrook, "Water for Elephants") foresees that he and Sean will once again cross paths. Ian Anthony Dale, Bill Smitrovich, Taylor Cole, and Lisa Vidal also star.