Season 8, Episode 16 (January 7, 1980). Written by Thad Mumford & Dan Wilcox; Directed by Burt Metcalfe.
This episode balances multiple storylines that converge in the operating room. Hawkeye is horrified to discover his monthly bar tab totals $38.20—a staggering sum—and vows to give up alcohol for a week [1].
His sobriety makes him insufferable: irritable, preachy, and annoying to his colleagues. Meanwhile, Charles Winchester receives word that his sister Honoria is engaged to marry an Italian man. His snobbish, bigoted reaction leads him to write furious letters home trying to stop the wedding.
The climax brings both storylines together when a North Korean POW smuggles a live grenade into the OR. Hawkeye grabs the soldier's hands, preventing him from releasing the pin, while everyone sings "Hush Little Baby" to keep the prisoner calm. Father Mulcahy finds the pin and puts it back in the grenade, saving the camp.
Afterward, Hawkeye enters the Officers' Club, orders a drink, then pauses and delivers the iconic line: "I'll be back when I want it, not when I need it."