Here's the official episode guide for Chuck season 4 episode 19, titled "Chuck Versus The Muuurder":
WHEN A SPY IS MURDERED IN CASTLE, IT'S UP TO CHUCK TO FIGURE OUT "WHO DONE IT"
- Chuck is put in charge of a top-priority mission, but his leadership skills are pushed to the limit when there is a murder in Castle.
- Awesome (Ryan McPartlin) takes on a mission of his own when Ellie finds an alarming new hobby.
- Morgan's leadership is also tested when his Buy More troops wage war against Large Mart.
- Yvonne Strahovski, Scott Krinsky, Vik Sahay, Mark Christopher Lawrence and Bonita Friedericy also star.