Wiktionary
very special episode
n. (context US English) A episode of an entertainment TV series that focuses on serious subjects instead.
Wikipedia
Very special episode
"Very special episode" is an advertising term originally used in American television promos to refer to an episode of a sitcom or drama series which deals with a really unpleasant, or controversial social issue. The usage of the term peaked in the 1980s.
Usage examples of "very special episode".
Or maybe Uday and Qusay could spruce up each other's rape rooms on a very special episode of Trading Spaces!