The narrator is coming back from the hyacinth garden with the hyacinth girl. These flowers are the symbol for death, therefore they might come back from a cemetery or a place, where there is no life.
After that the narrator focuses his attention on the girl: her arms are full and her hairs are wet. In front of her sensuality he cannot speak and his eyes "failed", it means that he weaken them because of her beauty: he cannot gaze into her eyes. In addition she makes him feel a sense of emptiness: he is not aware of himself, insomuch as he cannot understand if he is living or not and he doesn't know anything. In front of her he can only perceive the silence and the desolation and the emptiness of the sea ("Oed' und leer das Meer" expression taken from Wagner's "Tristan and Isolde"). In the scene run-on lines are frequent, in order to accelerate the rhythm.

The next scene deals with a famous clairvoyant, Madame Sosostris. Eliot borrowed the character from Aldous Huxley's novel Crome Yellow, where Madame Sosostris dresses up as a gypsy to tell fortunes at a fair. Eliot's aim of introducing her is to make some future prophecies.
Even if she has a bad cold, everybody knows her as the wisest woman of Europe, with a wicked pack of card. The adjective "wicked" underlines that the pack is considered as a fearful weapon. The reason is that Tarot cards can predestinate a cruel future. The clairvoyant invites him to watch the cards that she finds (using an expression taken from Shakespeare's The Tempest ): the drowned Phoenician Sailor, Belladonna, the Lady of the Rocks, the lady of situations, three staves, the Wheel, the one-eyed merchant and a blank card, that the clairvoyant cannot interpret. Instead she doesn't find "The Hanged Man".
Only the man with three staves and the wheel are actual Tarot cards; Belladonna is often associated with da Vinci's "Madonna of the Rocks," and the one-eyed merchant is, as far as we can tell, an invention of Eliot's.
Eliot himself explains why he choose these tarots in a note, that is contained in The Waste Land: "The Hanged Man, a member of the traditional pack, fits my purpose in two ways: because he is associated in my mind with the Hanged God of Frazer, and because I associate him with the hooded figure in the passage of the disciples to Emmaus in Part V. The Phoenician Sailor and the Merchant appear later; also the 'crowds of people', and Death by Water is executed in Part IV. The Man with Three Staves (an authentic member of the Tarot pack) I associate, quite arbitrarily, with the Fisher King himself".
But what does Madame Sosostris foretell? She foretells death by water. After that she sees a group of people "walking round in a ring" and then she concludes the forecast, inviting the narrator to say to Mrs. Equitone that she will bring the horoscope by herself.

The scene changes and Eliot refers to an Unreal City (making reference to Baudelaire's poem Les Sept Viellards (The Seven Old Men), one of the poems in the collection Les Fleurs du Mal The Flowers of Evil). Here the narrator sees a crowd over London Bridge under the brown fog in a winter day. People are so many and all of them exhale short and infrequent sighs. To render the idea Eliot uses two expression that remind Dante's Inferno: "I had not thought death had undone so many" and "Sighs, short and infrequent, were exhaled,".
They "Flowed up the hill and down King William Street, to where Saint Mary Woolnoth kept the hours with a dead sound on the final stroke of nine", that is the Church of Saint Mary Woolnoth , which has a bell, that when rings at nine o' clock, it seems to release a dead sound. There the narrator sees somebody he knows: Stetson. They met themselves at the battle of Mylae, that took place in 260 BC during the First Punic War. The narrator asks him if the corpse he planted the year before in his garden had sprout or not, if it would bloom that year or if the cold had disturbed its bed (the land) and he warns him to keep the dog far hence, in order not to dig it up again (expression taken from the Dirge in Webster's White Devil.)
Therefore Eliot comes back to the theme of fertility and regeneration and after that he concludes the first section of The Waste Land by using a verse of Baudelaire, Preface to Fleurs du Mal, addressing to the reader, who is considered his doppelganger, his brother, because they are destined for the same cruel future.