Governmental relations between Freedonia and Sylvania are governed by the tense relationship between Firefly and Ambassador Trentino and their rivalry for Mrs. Teasdale. The Sylvanian ambassador fears Firefly's influence because it has averted a revolution in Freedonia. When Firefly arrives at the tea party, greeted by the guests with the national anthem "Hail, Hail Freedonia," he dunks an invited guest's doughnut into a cup of coffee. He immediately competes with Trentino to charm Mrs. Teasdale with his attention:

Firefly: I can't give you wealth, but, uh, we can have a little family of our own (his eyebrows dance up and down)
Mrs. Teasdale: Oh Rufus!
Firefly: All I can offer you is a Rufus over your head.
Mrs. Teasdale: Your Excellency. I really don't know what to say.
Firefly: I wouldn't know what to say either if I was in your place. (To Trentino) Maybe you can suggest something. As a matter of fact, you do suggest something. To me you suggest a baboon.
Trentino: What!
Firefly: I'm sorry I said that. It isn't fair to the rest of the baboons.

Trentino, acting imperially, believes Firefly's conduct is inexcusable, and angrily walks away, insulting him: "You Swine!...You Worm!...You Upstart!" The third name-calling insult provokes Firefly to slap him with his gloves. Trentino fears the incident may plunge the two countries into war:

Trentino: Mrs. Teasdale. I'm afraid this regrettable occurrence may plunge our countries into war.
Mrs. Teasdale: Oh, this is terrible!
Trentino: I've said enough. I'm a man of few words.
Firefly: I'm a man of one word: scram!

As Trentino leaves and a rivalry between the two countries is sparked, Firefly boasts of his blue-blood heritage: "Why the Mayflower was full of Fireflys. And a few horseflies too. The Fireflys were on the upper deck, and the horseflies were on the Fireflys." Firefly calls for his car and to avoid being fooled again, insists on switching places with the chauffeur. So Firefly gets on the motorcycle and roars the engine, but remains frozen as Pinkie and the sidecar take off. Firefly quips again: "This is the only way to travel."

The next scene parallels the inevitable rivalry looming between the two countries. It is a silent, classic visual sight gag - a battle of rival concessions. The two street vendors (peanut vendor and lemonade vendor) clash again in a memorable pantomime encounter. The Lemonade Seller (with a new white straw hat) helps himself to a bag of peanuts and refuses to pay. When Pinkie, who is watching the stand for Chicolini, holds out his hand to be paid, the Seller paints his palm with mustard. Pinkie wipes his hand clean on the Seller's apron, cuts off the soiled portion with a big pair of scissors and throws it away. Pinkie knocks the bag of peanuts to the ground.

The Lemonade Seller then grabs another bag of peanuts. Pinkie immediately knocks it to the ground too. As he bends down, his new hat is taken and slowly roasted on the hot dog spit. The Seller is so aggravated that he overturns the peanut stand and then returns to his own lemonade vending stand to sell drinks to a long line of customers. Suddenly, everyone in the line disperses in shock. Pinkie has rolled up his trousers, perched himself on the edge of the clear glass lemonade tank, and is seen happily paddling and splashing with his bare feet in his opponent's lemonade tank.

Mrs. Teasdale tries to act as troubleshooter by entering into the conflict between Trentino and Firefly to bring reconciliation. She telephones from her place and urges Firefly to come over at once. Lounging in his bed and eating soda crackers, an image to mock the Idle Rich, Firefly takes the phone call from Mrs. Teasdale. On the verge of war, Firefly brings his plans for war to Mrs. Teasdale for safe-keeping. In her home, he shamelessly flirts with her and imagines them married: "Married. I can see you right now in the kitchen, bending over a hot stove, but I can't see the stove." He puts his arm around her as they sit on the sofa and shares his thoughts: "Oh, I was thinking of all the years I've wasted collecting stamps." He asks for a lock of her hair, after amending his request: "I'm letting you off easy - I was gonna ask for the whole wig."

Trentino and Vera enter from Mrs. Teasdale's porch. Trentino wants to avoid all-out war and attempts to reconcile their differences by being willing to do anything, but Firefly explains why war is inevitable:

Mrs. Teasdale: Your Excellency, the Ambassador's here on a friendly visit. He's had a change of heart.
Firefly: A lot of good that'll do him. He's still got the same face.
Trentino: I'm sorry we lost our tempers. I'm willing to forget if you are.
Firefly: Forget? You ask me to forget? A Firefly never forgets. Why, my ancestors would rise from their graves, and I'd only have to bury them again. Nothing doing. I'm going back and clean the crackers out of my bed. I'm expecting company.
Mrs. Teasdale: Please wait.
Firefly: Let go of me, you bully!
Mrs. Teasdale: Oh!
Trentino: I am willing to do anything to prevent this war.
Firefly: It's too late. I've already paid a month's rent on the battlefield.

Both Vera and Mrs. Teasdale beg Firefly - is there anything they can do to get him to reconsider and relent? Firefly replies: "Well, maybe I am a little headstrong, but I come by it honestly. My father was a little headstrong, my mother was a little armstrong. The headstrongs married the armstrongs and that's why darkies were born."

Firefly laughs away their silly conflict, but then prompts and even encourages Trentino to repeat the offending word from their previous encounter, causing their conflict to continue:

Trentino: Do you mean Worm?
Firefly: No, that wasn't it.
Trentino: I know Swine!
Firefly: ...No, it was a seven letter word.
Trentino: Oh yes, Upstart?
Firefly: That's it! Upstart.

Firefly slaps Trentino across the face with his gloves. Trentino departs, vowing Sylvania's declaration of war on Freedonia: "This means WAR!" Firefly adds:

Go, and never darken my towels again!

Trentino schemes to steal into Mrs. Teasdale's house to acquire the Freedonian war plans. Vera Marcal is a "weekend guest" in the Teasdale house - she is to act as an accomplice to help his hired spies, Pinkie and Chicolini. The same evening, Mrs. Teasdale has summoned Firefly to spend the night in her house for protection.

Attempting to break and enter into the Teasdale mansion to steal Freedonia's battle plans, Pinkie and Chicolini engage in an extended routine of being locked out. In the doorbell sequence, first the servant is locked out, then each of them are separately locked out, and finally, both of them are left on the outside. They ring a large bell and then the front doorbell and hide behind a hedge as a servant comes out to look around. Pinkie dashes inside the front door, but shuts the door on his partner. The servant is also locked out. Then Chicolini rings the bell, and Pinkie comes out to look. Chicolini slips inside and shuts the door on him. Pinkie is locked out. (The servant is still wandering about outside.) Then, when Pinkie rings the bell, Chicolini comes out and the servant comes back, goes in, shuts the door and locks both of them out.

They are successfully brought in another door by Trentino's accomplice Vera Marcal. She cautions them to be careful and absolutely quiet so they won't be detected: "If you are found, you are lost." Chicolini asks: "How can I be lost if-a found?" Although they are compelled to be as quiet as possible, Pinkie unavoidably makes loud noises with whatever he touches. Pinkie lights a loud hissing blowtorch for a flashlight. He also creates a virtual symphony of sound: the clock in the living room chimes, he triggers another music box playing "Who's Afraid of the Big Bad Wolf," and as he dances to the music, he plucks the piano strings like a harp. Chicolini finally stops the music by smashing Pinkie's hands with the piano top.

By phone, Firefly is awakened by Mrs. Teasdale who is worried about the security of the war plans. As Firefly prepares to go retrieve the plans from her, Chicolini locks him in his bedroom's toilet. Firefly helplessly screams: "Let me out of here. Hey, let me out of here, or throw me a magazine!" Pinkie and Chicolini both decide (independently and coincidentally of each other) to dress up in white nightshirts and nightcaps and masquerade as Firefly - adding his distinctive moustache, glasses, eyebrows, and cigar to their disguises. Chicolini then heads for Mrs. Teasdale's upstairs bedroom to ask her for the plans.

There in Mrs. Teasdale's room, she queries his Excellency about his "strange" accent, so Chicolini explains: "Maybe sometime I go to Italy, and I'm practicing the language." She writes out the combination to the downstairs safe where the plans are stashed. Pinkie, also dressed as Firefly, races into the bedroom - Chicolini hides under the bed, thinking it is Firefly. He puffs on his cigar, makes faces, honks his horn - and then abruptly leaves (with the safe's combination written on a piece of paper) after seeing his partner under the bed. Mrs. Teasdale, believing that she is alone, starts to undress. But Chicolini emerges from under the bed and she is startled:

Mrs. Teasdale: I thought you left.
Chicolini: Oh no. I don't leave.
Mrs. Teasdale: But I saw you with my own eyes.
Chicolini: Well, who you gonna believe, me or your own eyes?

She faints on the bed, thinking she is hallucinating, and Chicolini goes for water to revive her. When Chicolini hears the real Firefly approaching (after breaking out of the bathroom), he again hides under the bed. Firefly hears Mrs. Teasdale's question: "How about my glass of water?" A confused Firefly replies: "I give up. How about your glass of water?"

Sliding on the downstairs landing in stockinged feet, Pinkie (still garbed as Firefly) approaches the wall safe and turns the dials to unlock it. Like a radio dial, the safe begins to uncontrollably blare out a spirited rendition of a Sousa march - "The Stars and Stripes Forever" - and he tries desperately to turn off the sound, first by covering the safe with a pillow and a curtain, and then by spraying it to drown it with water.

Upstairs, Mrs. Teasdale is quizzical about all the noise:

Mrs. Teasdale: What's that?
Firefly: Sounds to me like mice.
Mrs. Teasdale: Mice? Mice don't play music.
Firefly (punning): No? How about the old maestro?

Firefly calls for guards at his headquarters (not "hindquarters") to surround the house. Leaving Mrs. Teasdale, he goes downstairs to find the source of the disturbance. To quiet the safe once and for all after smashing it, Pinkie drops the wall safe out the window. When he sees Firefly coming to investigate, Pinkie runs headlong directly into a large wall mirror, smashing it into pieces. The broken glass vanishes and a room is revealed beyond the mirror.

Next follows the inspired, celebrated mirror pantomime scene, a superlative, lyrical, artistic example of mute physical comedy [a revival of a classic vaudeville routine]. Pinkie (disguised like Firefly) confronts the real Firefly, and pretends to be his mirror image, simultaneously playing back every gesture and movement. Firefly suspects his "reflection," another white-nightgowned figure, and tests the reflection in the perfectly-timed, ghostly-silent pantomime to catch him.

• After peering closely at his mirror image, Firefly cups his hand on his chin, turns away, looks back over his shoulder (twice), bends down, and wiggles his backside. Pinkie imitates.
• Firefly nods his head up and down and moves to the left behind the door frame. Pinkie imitates.
• Firefly peeks around the door frame with his glasses moved down on his nose. Pinkie imitates.
• Firefly pokes his head around the lower edge of the doorframe on his hands and knees in a crawling position - and so does the reflection.
• Firefly tiptoes/prances by, hops back, and performs a one-legged hop back again. Pinkie imitates.
• Firefly does a traditional Charleston dance. Pinkie follows each step.
• Firefly then spins around completely, arms outstretched. In the first illusionary mistake, Pinky fails to spin around, but his image matches Firefly's after he has completed the gyration. Both images are posed with arms slightly outstretched in a half-bow. They both walk to the door frame, arms up and flailing.
• Firefly carries a white Panama hat hidden behind his back. Pinkie has something behind his back.
• Firefly changes sides with the mirror view. As they circle around one another back to their original positions, Firefly notices that his mirror image has a black top hat behind his back - he silently smirks triumphantly in anticipation of fooling and exposing the mirror image.
• Firefly claps the hat on his head as fast as he can to trick his mirror image. Miraculously, the mirror image claps an identical white hat on his head! Both make faces to try to send their mirror image into hysterics. Firefly then takes his hat off and bows. So does Pinkie.
• Pinkie drops his hat, and Firefly retrieves it and hands it back to him through the mirror frame.

When a third character - Chicolini - enters the scene's frame, the routine ends - the game of disguise is over, although it was over much earlier. Firefly grabs Chicolini by his nightshirt as Pinkie escapes.

After his arrest, Chicolini is brought to trial for high treason (for selling Freedonia's secret war code and plans), a capital offense - "CHICOLINI UNDER ARREST; FACES TRIAL FOR TREASON." "Spy Trapped Attempting to Steal War Plans at Gloria Teasdale Home. Firefly to Prosecute, Quick Conviction is Promised." The trial scene dialogue in the classic scene is entirely composed of outrageous, excruciatingly-shameless puns delivered in a sideshow atmosphere. Presiding prosecutor Firefly both attacks and defends him in the trial. Another stony-faced prosecutor (Charles B. Middleton) tells Chicolini that if found guilty, he will be shot:

Prosecutor: Chicolini, you're charged with high treason. And if found guilty, you'll be shot.
Chicolini: I object.
Prosecutor: You object. On what grounds?
Chicolini: I couldn't think of anything else to say.
Firefly: Objection sustained.
Prosecutor: Your Excellency? You sustained the objection?
Firefly: Sure. I couldn't think of anything else to say either. Why don't you object?
Prosecutor: Chicolini, when were you born?
Chicolini: I don't remember. I was just a little baby.

Feeling sorry for the defendant, Firefly takes over his defense after jumping over the judge's bench:

Firefly: (melodramatically) Look at Chicolini. He sits there alone. An abject figure.
Chicolini: I abject.
Firefly: (frowning) (To the court) I say, look at Chicolini, he sits there alone. A pitiable object. (To Chicolini) Let's see you get out of that one. (To the court) Surrounded by a sea of unfriendly faces.

To confuse the prosecutor, he begins another quiz game:

Firefly: Chicolini, give me a number from one to ten.
Chicolini: Eleven.
Firefly: Right.
Chicolini: Now I aska you one. What is it has a trunk, but no key, weighs 2,000 pounds and lives in the circus?
Prosecutor (unwittingly supplying the correct answer): That's ir-relevant.
Chicolini: Irr-elephant? Hey, that'sa the answer! There's a whole lotta irr-elephants in the circus.
Minister/Judge: That sort of testimony we can eliminate.
Chicolini: Thats-a fine. I'll take some.
Minister/Judge: You'll take what?
Chicolini: Eliminate. A nice, cool glass eliminate.

A defense, of sorts, is given for the defendant by Firefly:

Gentlemen, Chicolini here may talk like an idiot and look like an idiot, but don't let that fool you. He really is an idiot. I implore you, send him back to his father and brothers who are waiting for him with open arms in the penitentiary. I suggest that we give him ten years in Leavenworth or eleven years in Twelveworth.

Chicolini would rather take a different sentence: "I tell you what I'll do. I'll take five and ten in Woolworth." Before Chicolini is sentenced, a messenger interrupts and announces the news that Sylvanian troops are about to land on Freedonian soil for war. There is debate over the disastrous effects of an impending war:

Minister of Finance: Something must be done! War would mean a prohibitive increase in our taxes.
Chicolini: Hey, I got an uncle lives in Taxes.
Minister of Finance: No, I'm talking about taxes - money, dollars.
Chicolini: Dollars! There's-a where my uncle lives! Dollars, Taxes!
Minister of Finance: Aww!

"More bad news" arrives. Mrs. Teasdale enters to make one more final effort to prevent war. She brings Firefly the good news: "I've talked to Ambassador Trentino and he says Sylvania doesn't want war either." Without responding to the real issue, Firefly questions the way she has pronounced the word "either." She announces that Trentino has forgotten his quarrel with Firefly and is calling for a peaceful conference. Firefly compliments her for her noble deed:

I'll be only too happy to meet Ambassador Trentino and offer him on behalf of my country the right hand of good fellowship......But suppose he doesn't?

Firefly imagines being snubbed and his anger escalates. Firefly acts out what would happen if Trentino refuses to shake his hand - embarrassment, public humiliation - and then it is almost as if the rejection has taken place. Firefly cries:

Who does he think he is, that he can come here and make a sap out of me in front of all my people?

At that moment, Trentino enters with his entourage and his arms outstretched and willing to shake hands, but fantasy has become reality. The last-minute attempt at peace-making fails. Firefly greets him with another declaration of war: "So, you refuse to shake hands with me, eh?" and slaps him in the face. Trentino has no choice but to reply: "Mrs. Teasdale, this is the last straw. There's no turning back now. This means WAR!"

In the spectacular musical ensemble, "The Country's Going to War," the coming of war is celebrated by the four Marx Bros. and the people of Freedonia. [The scene is reprised within Woody Allen's Hannah and Her Sisters (1986).] The call to arms is lampooned with numerous parodies of musical styles including a patriotic parade, a Negro spiritual ("All God's Chillun Got Guns"), a hillbilly song ("Comin' Round the Mountain"), and a Virginia Reel barn dance:

They got guns
We got guns
All God's Chillun got guns

In a historical parody, Pinkie is dispatched to waken the citizenry with a bugle, in a memorable Paul Revere-like ride scene. While alerting citizens late at night on his white steed after seeing three lights ("they're coming by land and sea"), he comes upon a blonde woman undressing in an upstairs window. He gives up his Paul Revere midnight duties in the scene of exploded-expectations and enters her room, but is forced to find a place to hide in the bottom of a sudsy bathtub when her husband (Edgar Kennedy again) arrives home. And then, the husband settles into the bath tub on top of a submerged Pinkie. When Pinkie's taxi horn honk is heard underwater, he surfaces with bugle blowing, sounds a wet reveille and flees, leaving a startled husband in the tub.

Pinkie reaches his own house where a woman is waving to him from a second-floor window. He enters the front door on horseback. The next image is taken at the foot of the bed - Pinkie's discarded boots, a pair of ladies shoes, and horseshoes are all laid out on the floor. Perversely, Pinkie shares a bed with the horse, and the woman sleeps in a single bed alone.

In the war room, Firefly is dressed in a strange military uniform.

[He wears a different costume in almost every sequence until the end of the film, including various military outfits from the Civil War and Revolutionary War, a Boy Scout troop leader's uniform, and even a coon-skin Davey Crockett cap. All the war costumes suggest that the war scene symbolizes all American wars.]

He sends telegrams to the battlefront collect and because there isn't time to dig trenches, Firefly orders some ready-made: "Get them this high (gesturing up to his neck) and our soldiers won't need any pants...Get them this high (gesturing above his head) and we won't need any soldiers." Rival Trentino is also delivering equally absurd orders to Chicolini:

Trentino: There's a machine-gun nest near hill twenty-eight. I want it cleaned out.
Chicolini: All right. I'll tell the janitor.

Firefly is frustrated by war messages back and forth: "I'm sick of messages from the front. Don't we ever get a message from the side?" Firefly's secretary arrives in the besieged headquarters to announce that one of the generals is suffering a gas attack. To answer with more double entendres, Firefly offers an antidote:

Tell him to take a teaspoon full of bicarbonate soda and a half a glass of water.

Firefly asks his telegraph operator about communications:

Firefly: Any answer to that message?
Operator: No, sir.
Firefly: Well, in that case, don't send it.

A large shell bursts through an open window and blasts a large hole through the opposite wall. Firefly picks up his damaged Panama hat: "Gentlemen, this is the last straw." He asks for his Stradivarius - a violin case with a machine gun inside: "I'll show them they can't fiddle around with ol' Firefly!" Firefly picks up the machine gun and fires mistakenly on his own troops, boasting happily:

Firefly: Look at them run. Now they know they've been in a war.
Bob: Your Excellency!
Firefly (making the sound of rat-a-tat-tat) They're fleeing like rats.
Bob: But sir, I've got to tell you.
Firefly: (totally engrossed) Remind me to give myself the Firefly Medal for this.
Bob: Your Excellency, you're shooting your own men!

When told that he has returned friendly fire, he keeps it under his hat (metaphorically and literally). He offers Bob a banknote as a bribe to cover up his mistake: "Here's five dollars. Keep it under your hat. Never mind. I'll keep it under my hat."

Pinkie's main contribution to the war effort is to wander on the battleground's front lines with a sandwich board over his shoulders - a recruitment sign to gather more volunteers:

JOIN THE ARMY AND SEE THE NAVY

Chicolini, a spy for Sylvania and the Freedonian Secretary of War, enters the Freedonia headquarters and punches the time clock as he enters:

Firefly: Awfully decent of you to drop in today. Do you realize our army is facing disastrous defeat? What do you intend to do about it?
Chicolini: I've done it already.
Firefly: You've done what?
Chicolini: I've changed to the other side.
Firefly: So, you're on the other side, eh? Well, what are you doing over here?
Chicolini: Well, the food is better over here.

Firefly tries to keep gunfire and shells out by pulling down the blinds. Pinkie's hat twirls around on his head as it is hit by a rapid-fire machine gun. Mrs.Teasdale calls for rescue and Firefly delivers the famous line to his cohorts as they rescue her:

Remember, you're fighting for this woman's honor, which is probably more than she ever did.

Beseiged, they are soon running low on ammunition and overwhelmed by a counter-attack. When the house is hit by shells and it explodes, a large ceiling beam crashes to the floor in the shape of a cross or "X." A volunteer is selected to seek aid in a parody of the draft system. Pinkie hangs a "HELP WANTED" sign on the door, and then is chosen for the dangerous mission when Chicolini fools him in a circular counting game. As Pinkie prepares to march off, Firefly shakes his hand, kisses him, and makes fun of him:

You're a brave man. Go and break through the lines. And remember while you're out there risking life and limb through shot and shell, we'll be in here thinking what a sucker you are.

Pinkie cuts off the tail on Firefly's cap, and then falls backwards into a closet that explosively detonates with fireworks. Firefly telephones for assistance, sending help to the front. Stock footage shows the response to his call for aid:

- squadrons of fire engines
- battalions of motorcycle policemen
- marathon runners
- crew rowers
- long-distance swimmers
- packs of baboons/monkeys crossing a jungle footbridge
- herds of elephants
- schools of porpoises

When Firefly is shot in the rear-end, he cries: "They got me. Water!" Firefly gets a large white flower vase stuck on his head while drinking water from it: "Get me out of this! The last time this happened to me I was crawling under a bed." Pinkie removes the "Groucho" face-painted vase from his head by exploding a stick on dynamite inside it. Firefly emerges from behind a cloud of smoke: "Any mail for me while I was gone?"

Firefly keeps track of the war tally with a pool-hall counter. Freedonia finally emerges victorious and the war is won when Trentino rams the door and then gets his head stuck in the door of the Freedonian headquarters. Captured, he is pelted with apples until he surrenders.

The final line in the climactic absurd battle episode is delivered when Mrs. Teasdale cries:

Victory is ours!

She also attempts to sing to their victory with the glorious national anthem of Freedonia: "Hail, hail, Freedonia, land of the brave..." but is pelted with tomatoes, apples, and oranges.