Gelbart said that while writing the script for the episode, the “M*A*S*H” team knew they wanted Blythe Danner and wrote the character with her in mind. There was one little concern, however, as Gelbart explained:
“Only problem was, she didn’t do half hour shows and we didn’t yet have a script to show her. Gene Reynolds got her on the phone and we both made a very strong pitch to her, promising the part would be worthy of her talent. She took a chance, not seeing a word on paper. She was divine on the show. It’s still a personal favorite of mine.”
For an actor of Danner’s caliber to tackle a half-hour TV comedy in the mid-1970s (back when “TV” was still a dirty word to many entertainers), that’s a pretty big leap of faith. The episode needed someone who would be able to really go toe-to-toe with Alda in both charm and wit, and it needed a woman that people would believe was the love of Hawkeye’s life. Thankfully, Danner was the perfect fit and the two have incredible chemistry, making it believable when they end up having an affair despite the fact that Caryle is married and Hawkeye generally doesn’t mess around with women in relationships.