Part One: Most everyone is cleaning the operating room. Hawkeye and BJ are on the gas tanks, Margaret and the nurses are going through equipment, Klinger is scrubbing and mopping the floor and Frank is supervising. Klinger asks to be excused because his nylons are bagging all around the knees. Hawkeye tells him to get bigger knees. Margaret says she wants the floor to be clean enough to eat off of. Klinger says it's already cleaner than the tables in the mess hall. Frank tells Margaret he hopes the nurses are doing a good job. She says they are holding up their end and she wants him to go hold up his. He goes to tell Hawk and Beej that once hey finish checking their machine to check it again. BJ says to wake him when Frank's gone and pretends to take a whiff of the nitrous. Frank says that it isn't even hooked up. BJ says 'I told you this was a 'tankless' job.' Frank tells Klinger to put some elbow grease into mopping. Klinger says he's all out. Frank says not to talk back. Klinger holds his mop like a rifle but the mop head hits Frank in the face. He yells that Klinger did it on purpose. Just then Col. Potter comes in and asks what's going on. Hawkeye says Frank tried to eat Klinger's mop. Potter tells Frank that he put him in charge. BJ says that he's doing a great job: 'He's already washed his face and his shirt.' Hawk adds 'At the same time.' Potter asks why it's taking so long. Frank says that no one's following orders and everyone's grumpy. BJ says he's Grumpy. Hawk says Frank is Sneezy. Beej says Klinger is Bashful and Hawk says Margaret is Dopey. Potter says to get it done and try to get along. BJ sings 'Git along, little doggie...' Hawkeye said he had a long little doggie once, a Dachshund, but it 'mustard' out. Frank says to knock out the silliness. Hawk says to 'Knock yourself off, goofball!' Beej says he was invited to the Goof Ball but didn't have anything to wear. Margaret says they are making her sick and Potter agrees. She then walks across the floor, Klinger yells about it and Margaret says it's still filthy. Klinger yells about having no thanks for his work. She tells him not to yell at her because she's an officer. Hawk adds, 'But you're no gentleman.' The nurses laugh at that and she yells at them. Frank says it's been like that all day. Potter says to try and make the best of it. Everyone starts agreeing, but sarcastically. Potter leaves, Frank yells at them to have fun and Hawk and Beej throw their rags at him. Meanwhile, Potter and Radar are walking across the compound as Father Mulcahy drives up. He tells them that not only does he have the camp's mail, but a movie that the Colonel has been waiting for. In the OR Margaret tells the nurses to clean shelves even though it contradicts what she said before. Frank tells Hawk and BJ to step on it and Hawk says that if he says that one more time he'll step on Frank. He then says to 'move it.' The nurses start yelling, Hawk tells them to stop and Margaret says to mind his own business. Klinger says to stop walking over his clean floor. Radar announces over the PA that the Colonel wants to make an announcement. He tells Potter to keep his finger on the button, which can be heard over the PA. Potter announces that there is mail. Everyone cheers and Hawkeye says 'What's mail?' Potter also says he has a movie for everyone after supper but he's saving the title for then. He signs off with 'Bye bye and buy bonds.' He then says that he shouldn't have said that but he still has his finger on the button and he can be heard. Radar tells him, then takes the mic and says that the Colonel is finished. He reminds Potter about the button and he says he just forgot, but Radar still has his finger on the button and he points it out. Later. in the Swamp, Hawk is trying to write but his pen isn't working. He asks BJ for one but he just gives Hawk a pillow. Frank comes in and Hawk asks to borrow his pen, Frank says no, that the point is used to the way he writes. BJ says that his wife sent a Dutch apple crumb pie. He gives it to Hawk, he takes a piece and says it's really bad. BJ gets upset and takes the pie. Hawk says he'll be one of his pallbearers. BJ says not to bury him in the shirt Hawk brought me from Seoul, because one of the arms is longer than the other. Hawk says it's fine, and BJ says to wear it himself. He says he will, and go visit the nurses in it. But BJ is right, so Hawk moves his arms so the sleeves match and leaves. Then he goes to the nurses' tent but finds them in their dress uniforms. He invites them to the movie but Bigelow says no. Able says they have been invited to dinner at I-Corps with some chopper pilots. She says that they are tired of the same people and want to see someone fresh. Hawk says that he's always been fresh with her. He gets on his hands and knees and begs. Bigelow says no, and Hawk says that a man has to have some dignity and crawls out of the room. Frank goes to Margaret's tent and asks to talk to her. She reluctantly agrees. He says that he remembers the place and she looks good in the light. When she asks if that's all, he says he wants her to sit with him at the movie as just a friend. She agrees and he says that even though she's engaged, they can be civil. He offers to walk her back afterwards, but when he says they could play 'war games' like they used to, she says he lost and Donald won. He makes fun of his name and says that she's going to be Margaret Penobscott and their kids will be named Huey, Dewey and Louie. Margaret grabs her whip, says she's going to count to three and if he's still there, she's going to snap off his epaulets. He thinks she's bluffing but she skips two and goes straight to three. In the mess tent, Hawk and Beej are playing tic-tac-toe with peas and potato cubes. Hawk says the tension can be cut with a knife. BJ tries to use a butter knife but it isn't sharp and he says 'Not with this one.' Radar goes to throw away the food he didn't eat, but Frank stops him. He finds Radar didn't finish his peas, but Radar says they're hard as rocks. Frank says he's wasting food. He asks Radar if he knows that people are starving in Poland and Radar says they can have the tray. Potter asks what's wrong, and Frank says that he is garbage officer(Potter says everyone knows this) and he says that there's a tremendous waste of food, especially rutabaga, lima beans and liver. Potter asks if this is a surprise. Frank asks what would happen if the enemy got a hold of this and Potter says 'We'd win the war.' He then tells Frank that if there's any food left he thinks is edible, he can eat it. He leaves and Radar gives Frank his tray. Potter then goes into the mess tent and says that the movie will make new men out of everyone, except for the women. He says that it has three things that make a movie great: horses, cowboys and horses. He announces the title: My Darling Clementine. Everyone seems impressed. Frank says that he hasn't seen a good movie in ages. Hawkeye tells him not to be childish, but when he leaves Hawk starts laughing and says 'I'm so excited I could plotz!'
Part Two: The movie begins and everyone cheers. Klinger points out Ward Bond and when he shows his whip, Hawkeye says it's Margaret's. Hawk then mistakes Alan Mowbray and Klinger points him out. When Henry Fonda appears, everyone applauds. When Walter Brennan is seen, Klinger does his impression. Shortly after that, the film breaks. Everyone gets upset, Klinger says the film is full of splices, and Potter whispers something to the Padre, who leaves. Potter then leads everyone in a community sing. They all sing 'Tennessee Waltz' The nurses come out of their tent and see Mulcahy and a corpsman bringing the piano from the O-Club. Bigelow says he should have taken up the harmonica. Mulcahy tells her what's going on. Able says to have fun and Bigelow says 'Sounds like they're having it.' Klinger gets the film fixed and the scene where Wyatt Earp tells the Clantons that he's going to be the new marshal of Tombstone is seen. However, the light bulb on the projector burns out. He tries to find a new bulb, but playing with the old one raises the ire of the crowd, so Potter has Mulcahy start another song, 'Gee, Mom, I Wanna Go Home.' The Padre takes the first verse about having a collar around his neck: 'If you don't listen to him, you'll all wind up in heck!' Hawkeye and BJ take the next verse about surgeons being bright: 'We work on soldiers through the day and nurses through the night!' Potter sings about friendships being rare: 'So I spend all my free time carousing with my mare!' Klinger points out the nurses have come in and they take the next verse about doctors brains being profound, but they will take chopper pilots: 'They'll get you off the ground!' Radar is next, singing about corporals being green: 'But if it weren't for us guys you'd be in the latrine!' Klinger is next, singing that he thinks the Army is a mess: 'If it's so damn terrific, how come I wear a dress?' The crowd boo him and throw popcorn at him. Margaret finishes singing about nurses having not gotten married yet: 'But this one's gonna do it with Donald Penobscott!' As soon as they finish the song Klinger says he's fixed the film. However, the sound goes out soon after. Hawkeye says not to blame Klinger, that it's an Army projector. BJ says it's supposed to break down every five minutes. Hawk adds 'Like the peace talks.' Klinger gives up and calls for the lights. Potter says that he knows someone who does great movie star imitations and pulls Radar out of the crowd. Radar turns around to start it and Hawk says 'Radar's back!' Radar then does a John Wayne imitation. BJ guesses Barbara Bel Geddes and Hawk guesses The Mills Brothers. When Radar says who it was Hawk asks 'Who's John Wayne?' Radar then starts a Jack Benny impression with Klinger doing Rochester and Mulcahy doing Dennis Day. Then Frank tries a verse on Hawkeye and BJ thinking they're pretty smart: 'I'd like to take a scalpel and stab 'em in the heart!' However, no one sings the chorus with him and he fades out as he sits down. Then a Mulcahy soundalike contest starts up. Several people take his hat and speak with a high pitched voice. Radar's is particularly good and all Potter says is 'Jocularity! Jocularity!' Mulcahy starts to say something but everyone good-naturedly shouts him down. The film is fixed again just as the driver for the nurses pulls up. He asks for them and Hawkeye says 'I'll see your car and raise you Henry Fonda and Ward Bond.' Able says they're staying. The driver asks what he will tell the general and she says 'Tell him we're watching a movie with more stars than he has on his shoulders.' When the driver finds out what it is he says he just got a flat tire. Then the film breaks again and Hawkeye brings Margaret out to sing. Accompanied by the Padre, she sings 'C'est Magnifique.' Hawkeye punctuates the performance with comments. In the middle of the song the film starts again, but Margaret, oblivious to it, keeps singing even as the crowd tries to get het to stop. Then the movie's climactic shootout at the OK Corral scene is shown. When the shootout starts, the crowd hoots and hollers, then Hawkeye pretends to be shot. Margaret pretends to shoot him, then falls in Potter's lap. As the scene continues, everyone starts to fall over like they were shot. As the scene ends, an ambulance pulls up. The driver yells, 'Hey, we got wounded out here!' He goes into the mess tent, sees everyone fallen down and says 'We got wounded in here too.' He yells that they have wounded and everyone gets up and snaps into action.
Epilogue: In the OR, Potter starts singing 'My Darling Clementine' even while asking for a scalpel. Eventually others join in until the entire OR is singing along.