Finding out that their partner is involved in some kind of treason, Chuck and Sarah set out on a mission to help him turn the situation around.
Chuck and Sarah are given a strict order to capture someone they are familiar with, Casey. In the next "Chuck", Casey carries out a side mission for his old commanding officer James Keller that leads to him 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.
"Chuck Versus the Tic Tac" airs on Monday, March 15 on NBC. Robert Patrick, best known for his role as T-1000 in "Terminator 2: Judgment Day", guest stars as Keller.
On another news, NBC has started renewing its shows for the Fall 2010-2011 season. "Chuck" however is not yet mentioned but based on its third season rating, which averages 7.4 million, the show is again in the bubble.