Season 4, Episode 9 (November 7, 1975). Written by Dennis Koenig; Directed by George Tyne.
A shell-shocked officer, Captain Calvin Chandler (Joshua Bryant), arrives at the 4077th after walking twelve days through enemy lines. He refuses to talk, eat, or be examined—and Colonel Potter is convinced he's faking it. But Hawkeye, B.J., and Colonel Flagg (Edward Winter) each have their own reasons for wanting to crack Chandler open: Hawkeye out of clinical suspicion that the man really is sick, Flagg out of certainty that he's a spy [1].
The title—Latin for "Where are you going, Captain Chandler?"—is the recurring question the camp keeps putting to a man who has come unmoored from the war. The episode plays the question for both its psychological weight and its comedy, with Sidney Freedman (Allan Arbus) eventually arriving to cut through the various factions' competing agendas. As the MASH4077TV episode guide notes: "Both Colonel Flagg and Sidney Freedman drop by the 4077th, but this isn't a strictly social visit. Both Flagg and Freedman are trying to get custody of one of the 4077th's patients. Why? He thinks he's Jesus Christ" [2].
For Colonel Flagg, this is one of his most distinctive appearances. He is already complaining to Potter about the previous commanding officer: "The last C.O. in this unit couldn't make a command decision without a month's notice." Freedman's presence in the episode also provides a subtle continuity link back to "Deal Me Out," where Winter first played the Flagg archetype as the friendlier "Captain Halloran"—and where Freedman also appeared. Many fans read Halloran as a Flagg alias; Flagg's line to Freedman in this episode is read as an inside joke acknowledging that [1][3].
The episode is the first Flagg appearance under the new Potter regime, and the new commanding officer's weary professionalism provides an effective counterweight to Flagg's bluster.
[1] Quo Vadis, Captain Chandler? - Wikipedia [2] M*A*S*H Episode Guide - MASH4077TV [3] List of M*A*S*H characters - Wikipedia