The Mock Turtle sighs and pauses for a bit, crying to himself. Finally he tells Alice that she may not know what a Lobster-Quadrille is, and she says she doesn't. He explains that it's a dance, and the best way to explain it is to show it to her.
The Mock Turtle and Gryphon begin dancing the Lobster Quadrille for Alice's amusement. (A "quadrille" is a lively kind of Victorian dance, fashionable at the time Lewis Carroll was writing.)
As the Mock Turtle and Gryphon dance, they get more and more excited and begin shouting a description of the dance to Alice. Suddenly they finish the first "figure" – the first part of the dance – and become completely still.
Alice says she'd like to see more, so the creatures dance the first figure again, singing a tune for themselves. The Gryphon says he's forgotten the words, so the Mock Turtle sings a slow, sad song. Verse Alert!
The Mock Turtle's song is a silly story about a whiting and a snail dancing together with a porpoise, a lobster, and turtles.
When they're finished, Alice says that it was very interesting to watch, but really she's just glad that it's over.
The Mock Turtle and Gryphon keep asking Alice which sea-creatures she is familiar with. She begins describing seafood that she would eat at the table – lobsters covered in crumbs, and so on. Then she has to stop herself so that she doesn't offend her new friends.
The Gryphon tells Alice that the whiting (a crustacean) is called that because it "does the boots and shoes" in the sea, just like we use blacking to polish our boots on land.
Alice asks about the "porpoise" in the song, and the Mock Turtle replies with a play on words, interpreting it as "purpose."
The Gryphon asks to hear some of Alice's own adventures. Alice tells them the story of her travels through Wonderland, beginning with the White Rabbit.
When Alice starts explaining how she mis-recited "You are old, Father William," the animals are curious and ask her to recite another poem, "'Tis the voice of the sluggard." It's another Verse Alert!
Alice tries to recite the poem, but, of course, it comes out all wrong. Instead of being a moral lesson about a lazy boy, it becomes the story of a baked lobster. The Mock Turtle and Gryphon tell her she's talking nonsense.
Finally Alice gives up on reciting the poem, which she can't even explain. The animals offer to go on with the dance or sing her a song. Alice asks for a song, and – Verse Alert again! – the Mock Turtle sings a song about soup.
In the distance, Alice hears someone call out that the trial is beginning. The Gryphon takes her by the hand and they run toward the call. The Mock Turtle remains behind, still singing the chorus of his song about soup.