Summer Glau To Guest Star In Chuck

She'll be in episode eight of the new season playing… ah, now that would be a minor spoiler

“Hang on”, you might be thinking. “I saw Chuck this week, and Greta was played by Olivia Munn.” Well, yeah, but one of the gimmicks this season is that there'll be a new Greta every week – seems the character's name is an assignation. Other upcoming Gretas include Stacy Keibler and Isaiah Mustafa.