The speaker of the poem thinks of the 19th-century American poet Walt Whitman as he walks down dark streets. Speaking directly to an imagined Whitman, the speaker enters a supermarket, and notices all of the families shopping. He imagines he sees Federico Garcia Lorca, a Spanish poet and playwright, shopping for watermelons. Or something.
The speaker addresses Whitman again, and imagines that he sees him shopping for meat and asking questions of the grocery clerks. He wanders around the stacks of cans, and imagines that he's being followed by a detective. He then imagines that he and Whitman sample the food in the supermarket without paying for it.
The speaker feels lost, and asks Whitman where they are headed. He thinks of Whitman's book and feels silly. He then asks Whitman a number of big life questions. Will they walk all night? What has happened to "the lost America of love"? The poem ends when the speaker asks Whitman about his (19th-century) America, and imagines him as a mythological figure, standing on the shore of the river Lethe, the river of forgetting.