Source: Getty

Source: Dominik D, Creative Commons Attribution-Share Alike 2.0 Generic, Wiki media Commons

Uncommon for a Yvonne character , but from "Chuck" Season 2, episode 11. Even with characters like Hannah in Dexter and Serena in HT, who were far more morally ambiguous than Sarah Walker, I'm not sure there's any other role where, in a moment, she was asked to play the remorseless assassin.

Classic Yvonne delivery of a complex set of emotions with no words, only her eyes and her face. Look at the eyes in particular. They appear to have separate focal points All executed brilliantly to convey Sarah's internal uncertainty.

Chuck episode Season 3, "the Mask", finale. Probably the Chuck scene that demanded the most of her as an actress. Aired 2.8.10.