Captain Spaulding meets with the pompous philanthropist and art connoisseur Roscoe W. Chandler, and they both repeatedly introduce themselves - a mockery of introductions in general:

Spaulding: Yes, I've heard about you for a great many years, Mr. Chandler, and I'm getting pretty darn sick of it, too.
Chandler: Quite naturally, I have also heard of the great Captain Spaulding.
Spaulding: Well, that's fine. I've heard of you and you've heard of me. Now have you ever heard the one about the two Irishmen?
Chandler: Oh yes, ha, ha, ha.
Spaulding: Well, now that I've got you in hysterics, let's get down to business. My name is Spaulding, Captain Spaulding.
Chandler: I am Roscoe W. Chandler.
Spaulding: And I am Jeffrey T. Spaulding. I betcha don't know what the 'T' stands for?
Chandler: Uh, Thomas?
Spaulding: Edgar. You were close though. You were close, though, and you still are, I'll bet. Now this is what I want to talk to you about, Mr. Chandler. How would you like to finance a scientific expedition?
Chandler: Well, that is a question.
Spaulding (quips): Yes, that is a question. You certainly know a question when you see it. I congratulate you...there's one thing that I've always wanted to do before I quit.
Chandler: What is that?
Spaulding: Retire. Now, would you be interested in a proposition of that kind? You know, I've always had an idea that my retirement would be the greatest contribution to science that the world has ever known. This is your chance, Mr. Chandler, when I think of what you have done for this country. And by the way, what have you done for this country?

The absurdist, side-tracked conversation switches to Chandler's interest in art. Spaulding - with an illogical suggestion, proposes where Chandler might build an Opera House:

Chandler: Well, I've always tried to do what I could, especially in the world of art.
Spaulding: Art. Well, I don't know how we drifted around to that, but what is your opinion of art?
Chandler: I am very glad you asked me!
Spaulding: I withdraw the question! This fellow takes things seriously, it isn't safe to ask him a simple question. Tell me, Mr. Chandler, where are you planning on putting your new opera house?
Chandler: Oh, I thought I should like to put it somewhere near Central Park.
Spaulding: I see. Why don't you put it right in Central Park?
Chandler: Could we do that?
Spaulding: Sure, do it at night when no one is looking. Why don't you put it in the reservoir and get the whole thing over with? Of course, that might interfere with the water supply. But after all we must remember that 'art is art.' Still, on the other hand, water is water, isn't it? And east is east and west is west and if you take cranberries and stew them like apple sauce, they taste much more like prunes than rhubarb does. Now, uh - now you tell me what you know.

After more repetitive introductions and verbal brow-beating, Chandler is forced to continue the conversation - and he brings up finances: "In the last analysis, it is a question of money. The nickel today is not what it used to be ten years ago." This affords Spaulding another opportunity to run verbal rings around his opposing character. He delivers a memorable, nonsensical monologue on his own unique economic theory of thrift. He responds to Chandler's remark about the worth of the nickel by proposing how a 'seven-cent nickel' could solve the country's economic woes:

Well, I'll go further than that. I'll get off at the depot. The nickel today is not what it was fifteen years ago. Do you know what this country needs today?...A seven-cent nickel. Yessiree, we've been using the five-cent nickel in this country since 1492. Now that's pretty near a hundred years' daylight saving. Now, why not give the seven-cent nickel a chance? If that works out, next year we could have an eight-cent nickel. Think what that would mean. You could go to a newsstand, buy a three-cent newspaper and get the same nickel back again. One nickel carefully used would last a family a lifetime!

Chandler finds himself thinking that Spaulding has a fantastic idea:

Chandler: Captain Spaulding, I think that is a wonderful idea.
Spaulding: You do, huh?
Chandler: Yes.
Spaulding: Then there can't be much to it. Forget about it.

Chandler mistakenly calls Spaulding 'Captain Chandler,' and soon their identities become so confused that Spaulding turns toward the camera and asks for a programme from the audience to help sort it out. Chandler asks about South America and announces that he is sailing for Uruguay. Spaulding delivers a memorable pun:

Well, you go Uruguay and I'll go mine.

In the library, Arabella flirtatiously asks Ravelli to hang up John's facsimile canvas in place of the other painting. When he asks: "You want I should steal?," she replies: "Oh, no, no. It's not stealing," Ravelli tells her that he can't do it. He then speaks to the Professor about how they aren't making any money, because all he does is chase women. They are wasting their time and missing out on all the lucrative card games:

Ravelli: We make nothing. The first thing you know, we're gonna live on a-charity, then we go to the old ladies' home. How do you like that? (The Professor answers by grinning laciviously.) No, no, that's-a no good. These people here all a-got money. Now we gotta get someone to play with us, see. I play anything - poker, pinochle...

Just then, Mrs. Rittenhouse enters as an appropriate victim of their games. The Professor and Ravelli hand their legs to her several times - the beginning of hilarious pantomime gags. He also slaps her thigh so that her leg jerks up reflexively. Disgusted with being asked to play all kinds of games ("blackjack, sock-er"), Mrs. Rittenhouse decides, with Mrs. Whitehead, to sit down on a couch. She finds the Professor beneath her on the sofa. Mrs. Whitehead pushes the Professor's leg back and forth between her lap and Ravelli's lap. When Mrs. Rittenhouse tries to walk away, the Professor runs after her, hugs her, tries to sit in her lap, and then swings and misses with a wild punch, falling over. Ravelli starts a boxer's countdown that is interrupted by the sound of a bell.

The bell ends Round One - in this incredible boxing/wrestling match scene. After Round One, Coach Ravelli revives his fighter in the corner, fanning him, tickling his stomach and giving him instructions. A bell rings signaling Round Two. The Professor comes out swinging toward an unsuspecting opponent - he grabs Mrs. Rittenhouse and even punches her repeatedly in the stomach, causing her to rise into the air.

The two of them, notorious cardsharks, decide to settle down and team up to engage Mrs. Rittenhouse and Mrs. Whitehead in a lunatic-style bridge game "for small stakes." Hives and the Professor are at odds in putting up a portable card table. When finally seated, Ravelli asks: "How do you want to play...honest?" The Professor pulls out his blackjack, and puts it on the table. Mrs. Rittenhouse reaches out and tells him to put it away, and he accidentally hits his own hand when he attempts to whack her with it. Requesting sympathy for his bruised hand, he holds it out for Mrs. Whitehead to kiss and make well, then ferociously threatens to hit her if she does.

Drawing for partners, both cardsharks pick aces of spades in a game with the Professor cheating in every way imaginable. Mrs. Rittenhouse questions this improbability of such a coincidence: "Two aces of spades?" Ravelli answers: "Yeah, he's got thousands of 'em." The Professor is given his choice of seats, so he sits down on Mrs. Whitehead's lap. Ravelli interprets: "He thought it was contact bridge." The Professor shuffles the deck of cards, but he flicks through each half of the deck separately in each hand on the table, so that they are actually unmixed. Mrs. Rittenhouse cuts the cards twice (not really). Then, wetting his left thumb, the Professor deals with his right hand, giving Ravelli a quick peek at each card to see if he wants it. If he is not happy with a card, he tosses it away into the air. If Ravelli rejects a card, it is dealt to Mrs. Rittenhouse, who doesn't notice while she is busy sorting her hand.

Incredibly, the two lady partners end up with strong bridge hands and raise the bidding in spades. So the Professor switches Mrs. Rittenhouse's cards with his own - and she exclaims with surprise: "Why, I haven't a spade in my hand!" Ravelli acquiesces: "All right, we double."

In a new round of bidding with the same dealt hand, the Professor bids one. Mrs. Whitehead asks: "One. One what?" Ravelli answers: "That's all right, you'll find out," and then bids two of the same suit. The Professor instructs Mrs. Whitehead to lead the game with an ace of spades, and then trumps it, with Ravelli calling it a "finesse." Ravelli warns his partner twice: "No spades, partner...No spades!!!" Taking him literally, the Professor rips his card into small pieces. Ravelli calls Mrs. Whitehead "the dummy." Because it is not clear which suit is trump, the Professor plays thirteen aces (half of them the ace of spades), winning every hand. Ravelli tells them: "Ace of spades, Ace of spades...He plays a good game." As the ladies leave the game table upset by the blatant cheating, the Professor wobbles off in Mrs. Whitehead's stolen shoes.

Arabella has convinced Ravelli and the Professor to sneak into the library, that rainy evening, and install John's painting. Ravelli asks the Professor for a flash-light, but is misunderstood because he mispronounces the word: "Where's the flesh?" The Professor suggests part of his cheek, a dead fish, a flask, a flush of cards, a spray can of Flit, and a flute before realizing that Ravelli has asked for a flash-light. The thunderstorm causes the lights to go out. Captain Spaulding and Mrs. Rittenhouse enter in the dark, sit on the sofa, and hear hammering and pounding. Spaulding tells her what he thinks the noise is: "...you got roaches...and the biggest one has got asthma." After the two sneaks leave, the lights go on again. They first exit out one side of the library, but because there is pouring rain there, they choose the other side where there's "California" sunshine.

In front of a large audience of guests in the film's most legendary and memorable scene, Captain Spaulding recounts a hilarious account of his adventurous African safari:

Spaulding: Africa is God's country, and He can have it. Well, sir, we left New York drunk and early on the morning of February 2nd. After fifteen days on the water and six on the boat, we finally arrived on the shores of Africa. We at once proceeded three hundred miles into the heart of the jungle, where I shot a polar bear. This bear was six foot seven in his stocking feet and had shoes on...
Mrs. Rittenhouse: Pardon me. Just a moment, Captain, just a moment. I always thought that polar bears lived in the frozen North.
Spaulding: Oh you did! Well, this bear was anemic and he couldn't stand the cold climate. He was a rich bear and he could afford to go away in the winter. You take care of your animals and I'll take care of mine. Frozen North, my eye! From the day of our arrival, we led an active life. The first morning saw us up at six, breakfasted, and back in bed at seven - this was our routine for the first three months. We finally got so we were back in bed at six thirty. One morning, I was sitting in front of the cabin, smoking some meat.
Mrs. Rittenhouse: Smoking some meat?
Spaulding: Yes. There wasn't a cigar store in the neighborhood. As I say, I was sitting in front of the cabin when I bagged six tigers.
Mrs. Rittenhouse: Oh, Captain!
Spaulding: Six of the biggest tigers...
Mrs. Rittenhouse: Captain, did you catch six tigers?
Spaulding: I bagged them. I...I bagged them to go away, but they hung around all afternoon. They were the most persistent tigers I've ever seen. The principal animals inhabiting the African jungle are moose, elks and Knights of Pythias. Of course, you all know what a moose is. That's big game. The first day, I shot two bucks. That was the biggest game we had. As I say, you all know what a moose is? A moose runs around on the floor, and eats cheese, and is chased by the cats. The elks, on the other hand live up in the hills, and in the spring they come down for their annual convention. It is very interesting to watch them come to the water hole. And you should see them run when they find it is only a water hole. What they're looking for is an al-co-hole (or elk-a-hole). One morning, I shot an elephant in my pajamas. How he got in my pajamas, I don't know. Then we tried to remove the tusks. The tusks. That's not so easy to say, tusks. You try that some time...As I say, we tried to remove the tusks, but they were embedded in so firmly that we couldn't budge them. Of course, in Alabama, the Tusk-a-loosa. But, uh, that's entirely ir-elephant to what I was talking about. We took some pictures of the native girls, but they weren't developed. But we're going back again in a couple of weeks.

Out of her old-fashioned concern for propriety (after Spaulding's remark about 'developing' native girls), Mrs. Rittenhouse discreetly but abruptly concludes the lecture. Chandler calls out:

Hooray for Captain Spaulding. Three cheers for Captain Spaulding. Three cheers for Captain Spaulding. Three cheers...!

The Professor obliges by bringing over three chairs for Captain Spaulding. Spaulding instructs Ravelli to entertain the guests with piano playing (Chico's specialty):

Senor Ravelli's first selection will be 'Somewhere My Love Lies Sleeping' with a male chorus.

Ravelli monotonously repeats part of "Sugartime" as if it were a dull piano exercise or broken record, because he has forgotten how it ends.

Ravelli: I can't think of the finish.
Spaulding: That's strange, and I can't think of anything else.

During another piece, the Professor clangs two horseshoes together and they rhythmically beat out part of the Anvil Chorus. Spaulding proposes to give a gift of a hope-chest to Mrs. Rittenhouse "at a very low figure." She gushes:

Mrs. Rittenhouse: Oh, how wonderful, Captain!
Spaulding: Now don't be too hasty. Wait till you see it. This is all hand-painted. The whole thing was done with the white of an egg.
Mrs. Rittenhouse: Well, what is it, Captain? What is it?
Spaulding: What is it, you ask? This is a hope chest for a guinea pig. What is it? (With his hand on his chest) This magnificent chest - no this mag...(he points toward her massive chest) - no (he points toward the long wooden chest) this magnificent chest. I now take great pleasure in presenting to you with my compliments.
Mrs. Rittenhouse: Captain, this leaves me speechless.
Spaulding: Well, see that you remain that way.

As the guests adjourn and file into the library, a stealthy Hives is seen leaving with John's facsimile painting under his coat. He has replaced it with Mrs. Whitehead's phony copy. During the gala unveiling of the priceless Beaugard oil painting (actually the second fake that the butler has put in its place), Chandler determines that the canvas is an inferior fake ("a rank imitation"). Spaulding volunteers to help and declares: "Leave it to me. I'll throw some light on this subject," and the lights immediately go out during a power failure. When they come on, even the fake has disappeared from above the mantle. Nerve-wracked and anxious, Hives (an ex-convict) tells Mrs. Whitehead and Grace his worries that the police will be summoned and that he will become a prime suspect:

Grace: Why, they wouldn't suspect you?
Hives: Of yes, they would. You see, the last time they suspected me, I got four years.

To his wide-eyed dismay, he also discovers that his copy of the painting has also been stolen. Hives immediately suspects the Professor and decides to render him unconscious (with a few drops of a knock-out ether solution on a handkerchief).

In the garden with John, Arabella is pleased that they had their fake installed in place of the Beaugard - and that it was stolen by thieves: "Supposin' the thieves had gotten away with the Beaugard...What would Mother do? Why, it's worth $100,000 dollars. How could she have replaced it?" They find it an appropriate occasion to sing a love song to each other, "Why Am I So Romantic With You?" And Harpo plays a requisite harp solo before yawning and falling asleep.