A Congressional aide, Williamson, visits the 4077th on a supposedly routine fact-finding tour, but it's discovered that his motives are far deeper - too uncover Margaret as a communist sympathizer. His case is full of innuendo, so the gang set out to help Margaret.

A beautiful and ambitious young nurse, Harris, who plans to become a doctor when she leaves the Army, finds herself in a misunderstanding with Father Mulcahy. Meanwhile, the camp's water supply is depleted, and the rest of the 4077th is more concerned about where their next shower will come from.

A brawl at Rosie's Bar puts Rosie in the hospital, and the 4077th doctors are pressed into service as temporary saloon-keepers. Meanwhile, Father Mulcahy is apprehensive that his long-pending promotion to captain will again be denied. Potter: "The Pentagon. Weird looking building. Four walls and a spare. Monument to Murphy's Law."

Horrified by the gigantic size of his monthly bar tab at the officer's club, Hawkeye vows to give up booze for a week. Meanwhile, Winchester desperately tries to halt his sister's impending marriage to a man he considers unworthy of the Winchester heritage.

Klinger redecorates his quarters, but the resultant ridicule he receives drives him to new heights in his efforts to get out of the Army. Meanwhile, the doctors are perplexed by the reaction of an Asian-American war hero who tries to kill himself when he's told that he will be going home. Sidney Freedman is called in to assist.

Angered by the way civilian doctors in the States are profiting from the war, Hawkeye presents the Army with a bill for his medical services. Meanwhile, Charles reluctantly demonstrates American medical practices to three Korean medics, and is on the receiving end of their medical expertise.

Father Mulcahy counsels a GI who is plagued by guilt because he has swapped tags with a dead colleague. Meanwhile, B.J. and Charles consider ways of keeping a soldier-salesman quiet.

On the eve of a big poker game, B.J.'s pride is bruised when he finds out his wife is working as a waitress. And Potter takes driving lessons from Klinger.

Hawkeye is the golden boy of the world press when he treats a celebrity prizefighter, 'Gentleman' Joe Cavanaugh, who has a stroke at the 4077th. Father Mulcahy finds the news hard to take, as Cavanaugh was a hero of his.

Posing the theory that people will believe in anything, Charles and Hawkeye start a rumor that Marilyn Monroe plans to visit the 4077th, which gets everyone excited. Meanwhile, B.J. feels responsible when he's unable to rescue a wounded soldier, and is less than impressed when he is presented with a Bronze Star.

Hawkeye and the crew surprise Colonel Potter with a party to commemorate Mildred's final payment on the couple's mortgage.

Margaret and Hawkeye work on a time capsule to commemorate their time in Korea; Rizzo and BJ goof around with a fake hand grenade; Klinger becomes smitten with a young, pretty Korean war criminal.

Hawkeye is sent to a mental hospital; a freak accident causes Father Mulcahy to lose his hearing; Margaret worries about her post-war plans; Charles run across a band of Chinese musicians; BJ is sent home, much to Hawkeye's dismay; Klinger decides to stay in Korea to marry Soon-Lee; a ceasefire is declared, ending the war.