S3, E10: Casey carries out a side mission for his old commanding officer, Colonel James Keller (guest star Robert Patrick - Terminator 2: Judgment Day, The Unit, The X Files), but it leads to Casey committing treason. When Chuck learns the dark truth about Col. Keller, he and Sarah set out to break Casey out of jail and clear his name. Meanwhile, Awesome's plan to keep Ellie out of danger gets more difficult when she gets her dream fellowship.