Edward Winter played Colonel Sam Flagg, the overzealous Army Intelligence agent who paid several unwelcome visits to the 4077th. In his first guest appearance in "Deal Me Out" (episode 37, season 2), Edward Winter played an Army Intelligence agent named Captain Halloran. Some fans say Captain Halloran and Colonel Flagg are the same, pointing out in "Quo Vadis, Captain Chandler?" (episode 81, season 4) when Sidney mentions playing poker before with Flagg at the 4077th. However, other fans will argue that Halloran and Flagg can't be the same character. In Winter's second appearance, "A Smattering of Intelligence" (episode 48, season 2), Colonel Flagg is introduced to the 4077th as someone they'd never met. Regardless, Edward Winter was in a total of 7 M*A*S*H episodes. Winter also played Flagg in "Trials," an episode in the second season of AfterMASH.
Colonel Flagg did everything he felt was necessary to protect "the American way of life" and win the war. For him, this task included selling penicillin for information and having a wounded North Korean operated on so that he could face execution later. Flagg always had his own ridiculous conspiracy theories and even more ridiculous plans. He strongly disliked Hawkeye, Trapper, and B.J. because they wouldn't cooperate with him and his plans.
"Nobody can get the truth out of me because even I don't know what it is. I keep myself in a constant state of utter confusion."
When Frank learns a wounded soldier is an intelligence officer, he refuses to operate until another intelligence officer arrives. Frank
is more worried about the officer uttering some secrets while sedated than he is about the officer dying without an immediate operation.
Once Hawkeye and Trapper hear of this patient, they abandon the medical conference (poker game) and operate on the patient against
Frank's objections. When Captain Halloran, an intelligence agent, arrives, Frank explains what happened and Halloran goes to arrest
Hawkeye and Trapper. After they assure Halloran that their patient didn't say anything during the operation, Halloran joins the poker game.
Breaking his arm in a helicopter crash, Colonel Flagg, a intelligence officer, is brought to the 4077th. Flagg tells Henry that he's
with the CIA and threatens action if Henry reveals his real identity to anyone else. Soon after Flagg's arrival, Vinnie Pratt, an agent
with Intelligence G-2, arrives to find out what Flagg is up to. Pratt proceeds to tell Henry his identity and threatens action as well.
Each agent believes the other is following a hot lead on a security leak in the 4077th. Hawkeye and Trapper plant a phony file in
Frank's name and allude to both Flagg and Pratt that Frank might be a spy. After Flagg gets one phony file, Radar switches files so
that Pratt gets a different one. The next day, Flagg tries to arrest Frank for being a Communist
and Pratt tries to arrest Frank for being a Fascist. Hawkeye and Trapper then reveal it all to be a joke.
While Henry is away in Seoul, Burns and Houlihan are in charge, and
Hawkeye is the officer of the day. Colonel Flagg arrives at the 4077th with a North Korean whom he had shot. Flagg
tells Hawkeye he needs his captive operated on so he can be executed in Seoul. Hawkeye and Trapper operate on the Korean but refuse
to sign his release. Flagg tries to get Frank and Margaret to help him get the patient released; when that idea doesn't work, Flagg
threatens Hawkeye and Trapper. They finally agree to release their patient. When Flagg pulls up the ambulance to pick up his captive,
Hawkeye has Klinger secretly loaded onto the truck instead.
Thieves try to steal penicillin from the supply tent and one of them, named Perkins, is capture. Colonel Flagg arrives to
question him and unsuccessfully tries to get custody of him from Henry. Once alone with Perkins, Flagg frees him and proceeds
to beat himself, later blaming it on Perkins. At night, Hawkeye and Trapper rush into the supply tent after another thief is
discovered...only this time it's Flagg. Colonel Flagg reveals he was trying to get the penicillin so it could be bartered
for information. Perkins is recaptured and found to be a medic who was trying to get supplies for his unit. Hawkeye and Trapper
drug Flagg's coffee, giving him intense pain which they diagnose as appendicitis. The only penicillin Flagg ends up receiving
is used on himself.
When a wounded officer claims to be Jesus Christ, Potter sends for Sidney Freedman and Frank sends for Colonel Flagg.
When the soldier's true identity is discovered, Flagg wants him sent back to work as a bombardier. Sidney suggests that
Captain Chandler, the bombardier, needs help and will never be a soldier again. Flagg reacts by threatening to have Sidney discharged
from the Army for not signing his loyalty oath. Flagg changes his mind and decides to keep Sidney in the Army where they can keep
an eye on him.
After hearing that North Korean prisoners have been released in the area, everyone is worried when Margaret seems to disappear.
Colonel Flagg arrives and considers everyone a suspect before deciding that the Chinese must have abducted her. He orders Radar to
phone for everything he needs to find Margaret...including a box of scorpions. Soon thereafter, Margaret returns with the Korean
baby whom she had been delivering.
Colonel Flagg arrives at the 4077th, playing his usual spy games, convinced that Hawkeye is a Communist sympathizer. Flagg tries to get Charles to help obtain incriminating evidence. Charles plants phony evidence near a North Korean patient which leads Flagg to believe Hawkeye is going to hold a secret meeting. Flagg has MPs arrive to help arrest people at the meeting. After Hawkeye, Potter, and two Koreans go into the Swamp, Flagg barges in to break up the meeting. He tries to arrest everyone for a Communist conspiracy only to find out the two Koreans were the mayor and chief of police of Ouijongbu and they were playing bridge.