Casey (Adam Baldwin) carries out a side mission for his old commanding officer James Keller (guest star Robert Patrick) that leads to him committing treason. When Chuck (Zachary Levi) learns the dark truth about Col. Keller, he and Sarah (Yvonne Strahovski) set out to break Casey out of jail and clear his name. Meanwhile, Awesome's (Ryan McPartlin) plan to keep Ellie (Sarah Lancaster) out of danger gets more difficult when she gets her dream fellowship. Joshua Gomez also stars.

Following the casting of Quantum Leap’s Scott Bakula as Chuck’s dad, sources confirm to me exclusively that another sci-fi icon has been tapped for the show. Robert Patrick, a.k.a. the T-1000, is slated to appear midway through the third season.
But rather than coming from the future, Patrick will play Col. Keller, a mysterious figure from Casey’s past in “Chuck Versus the Tic Tac,” which I hear will be a big episode for Adam Baldwin’s newly-minted colonel.