A rumour that there's going to be a practive bug-out causes anxiety. When Potter assembles the unit in an attempt to squelch the rumor, the call comes in to bug out, and the rumour suddenly comes to life! Meanwhile, Hawkeye begins surgery on a patient with a spinal injury. The bug-out proceeds without him, Hot Lips and Radar, and they quickly learn after the unit departs that they're in the midst of the front. When Potter, Mulcahy, BJ, Frank and the others arrive at the buildings which had been scouted by helicopter, they find the house full of "business girls," and Potter gives them Klinger's dresses to persuade them to leave the house. A helicopter comes to evacuate the spinal injury patient, and just as the three get ready to go to the new location, they find the 4077 is already returning, and eventually everyone reunites back at the camp, what with the Chinese being repulsed.

Margaret, calling from Tokyo, holds the camp in suspense until she returns with the news of her engagement to Lieutenant Colonel Donald Penobscott. Frank Burns takes the news hard and arrests a Korean family as spies.

While fixing a stove that explodes, Hawkeye's face is badly burned. His eyes are bandaged, and it is not known if he will ever see again. Meanwhile Frank bets on the outcome of a baseball game, which he has already heard on the radio. After much tension in the camp the bandages come off, and happily, Hawkeye can see again.

Following an offer of promotion made by Master Sergeant Woodruff at a poker game, Radar is promoted to the rank of lieutenant. Finding this position awkward, Radar opts to return to his position as an enlisted man.

When Hot Lips confines Nurse Baker to her quarters, little does she know that Baker's husband has arrived in the camp. Hawkeye and B.J. put them together in Hot Lips' tent, telling everyone that a quarantined patient has been placed there. When Hot Lips discovers what has happened, she breaks down and refuses to press charges.

After hearing that North Korean prisoners have been released in the area, everyone is upset when Margaret disappears. Colonel Flagg is called in to investigate, and bungles things in his usual manner. Finally Hot Lips returns, after helping in the birth of a Korean baby.

Sidney Freedman, feeling depressed, visits the 4077th to observe how they fare under the pressures of war. He begins a letter to Sigmund Freud as a form of self-therapy, and releases his tension in the form of a practical joke with B.J., aimed at Frank Burns.

After Frank discovers that Danny Fitzsimmons has shot himself to get out of combat, Father Mulcahy is called in. Realizing his lack of understanding of the fighting, Mulcahy accompanies Radar to an aid station, where they encounter the real war at first hand. Mulcahy performs an emergency tracheotomy, guided by Hawkeye over the radio.

When Dr. Syn Paik, a North Korean surgeon, arrives with some wounded, he is passed off as a South Korean by Hawkeye and B.J., but to no avail. Hot Lips and Frank try to convince Potter that Paik is a spy. Paik, Hawkeye, and B.J. agree that it would be in the interest of all for Syn to leave.

After 24 hours of surgery, Hawkeye and Potter venture off to a Korean hospital to lend a hand. Hawkeye is appalled to learn that he must carry a gun. After helping the Koreans, they are shelled on the way back. They scramble from the jeep before it is shelled, and Potter urges Hawkeye to shoot in self-defense, against Hawkeye's will, and he does...into the air.

While Colonel Potter goes to Tokyo on R&R, his horse develops colic. Klinger becomes chronically depressed, and Hot Lips gets appendicitis. The horse is flushed out with a hose, Hawkeye and B.J. perform an appendectomy on Hot Lips, and all are well when Potter returns, except Klinger. Potter offers Klinger a discharge for severe depression, and Klinger gets very excited, which loses him the discharge.

After Potter orders Radar to move a Korean spirit post believed to ward off evil spirits, things mysteriously begin to go wrong. When an old Korean man is brought into camp for medical attention, he refuses surgery unless the spirits in the camp are exorcised. A priestess is brought in, who exhibits her dance and her bells and chants. All is well, and Radar returns the spirit post to its original position.

After Hawkeye bemoans the young age of the wounded, he appears to develop problems. Sleepwalking and bad dreams, according to Sidney Freedman, are taking Hawkeye back to a simple time, but the horrors of war continue to intrude. After Sidney's assurances that he is as sane as can be, Hawkeye's life once again seems to settle down.

Radar gets accepted into the "Famous Las Vegas Writers School", and begins to write his impressions of the camp. It happens to be Frank's birthday, so Hawkeye and B.J. stage a fight with each other to make Frank happy. Radar: "Dear Mum, I gave up the writing course on account I found out I can write better as myself than as Hemingway, O'Neill, or any of those other bums. Simplistically yours, Walter."

Befuddled by a crossword puzzle, Hawkeye persuades his old friend Tippy Brooks, a whiz at puzzles, brought to camp. Tippy arrives with his commanding officer Admiral Prescot, thinking it's a medical emergency. Having scrubbed up and helped out with the wounded they provided the needed solution to the puzzle.

Lieutenant Colonel Harold Beckett lies wounded in post-op waiting to get back to the front for five more days of combat duty to get his promotion. Meanwhile, Cho Lin, the Ping Pong champ, is engaged to Soony. He leaves to get her a ring, when the South Korean army conscripts him. He arrives at the 4077th as a wounded soldier, and after being patched up he is married at the camp.

Billy Tyler, a young black sergeant, is brought into camp with a bullet wound in the leg. He is a football player, and when he discovers that his leg has been amputated, he wants to die. After talks with Radar, Billy agrees that he must live on.

Nurse Carrie Donovan receives a "Dear Jane" letter from her husband, and practically falls apart. B.J. consoles her, and they spend the night together. Feelings of guilt come over B.J. until he discusses them with Donovan and the air is cleared.

Father Mulcahy comes down with infectious hepatitis, and Hawkeye has to give the whole camp antibiotics, whilst dealing with a psychosomatic back pain. Meanwhile, B.J. has to perform a very difficult operation.

In the midst of Hawkeye being considered, much to his distaste, for the position of a general's personal physician, Radar becomes a surrogate father to a Korean woman and her baby, until the baby's GI father returns.

As a cure for the increased tension at the 4077th, Potter obtains a copy of his favorite film, "My Darling Clementine", and makes a social event out of it. As the film continues to break, tensions rise, until Mulcahy plays the piano, Radar does his impersonations, and everyone acts out scenes from the film.

Korean children and American soldiers are often badly wounded when they hunt for souvenirs which the enemy have booby-trapped. Potter asks for it to stop, and Hawkeye and B.J. put a local junk dealer out of business.

In the midst of a deluge of patients and their individual medical histories, the 4077th is out of blood. Everyone in camp is donating at 48-hour intervals when a truckload of Turkish soldiers arrives to offer their blood and save the day.

Prompted by pressure from Frank, Hot Lips sets a date for marriage with Lieutenant Colonel Donald Penobscott. When Donald arrives in camp for the wedding, a bridal shower and bachelor party are given. When he has passed out drunk, Hawkeye and B.J. place Donald in a body cast and convince him that he has broken his leg. The ceremony is performed and Donald and Hot Lips leave for a week's honeymoon in Tokyo.