The train stops and Harry gets off to make his way to the school [carriages], wondering aloud why Hagrid is unexpectedly not around, when he's stopped in his tracks by the sight of horses pulling the school carriages. Asking his friends about them, he discovers that nobody else can see them, except for Luna, and he uneasily gets into the carriage to head for Hogwarts.

Chapter 11 - "The Sorting Hat's New Song" - In which the start-of-term feast takes place, the Sorting Hat gives warning in its new song, Harry recognizes Dolores Umbridge as she is introduced as the new Defense Against the Dark Arts teacher, and Harry learns that not everyone believes that Voldemort is back.
En route to Hogwarts, Ginny, Luna, Harry, Ron, and Hermione discuss [Hagarid] and his absence, and Harry continues to marvel at the horses that are now pulling the school [carriages].
In the Great Hall, Hagrid is still obviously missing, but Harry does notice [Umbridge] and [Professor Grubbly-Plank] sitting at the head table. Quickly, however, the [first years] arrive, along with the school Sorting Hat, to prepare for the sorting.
The Welcoming Feast
For the third time, Harry hears the Sorting Hat's song - but for the first time, it is not a jolly tune, but an ominous warning of the need for solidarity between houses. The students don't have much time to discuss it, though, as the sorting soon begins.
As the sorting concludes, [Dumbledore] briefly welcomes the students and lets the feast begin. As everyone eats, Nearly Headless Nick discusses the Sorting Hat's previous songs, though Ron promptly manages to insult him and he departs, as the students eat the rest of the meal.
With the feast over, [Dumbledore] once again gets up to speak and introduces [Umbridge] and [Professor Grubbly-Plank], but is soon interrupted by [Umbridge]. She speaks for a bit about the [Ministry of Magic]'s role at Hogwarts, but Harry drifts off and misses the edge of the speech, and before he knows it, the speech is over and the school dismissed - though not before Hermione summarizes the speech for him: "The Ministry is interfering at Hogwarts."
As the welcoming feast is dismissed, Hermione and Ron lead the [first years] to Gryffindor Tower and Harry quickly realizes much of the school is terrified of him, thanks to the [Daily Prophet]. With a little help on the password from Neville, he then gratefully makes it up to his [dormitory].
In his [dormitory] Harry runs into [Dean] and Seamus, and learns that Seamus doesn't believe or trust him. Neville backs Harry up, but Harry still goes to bed wondering what his treatment will continue to be like, and whether [Dumbledore] is facing the same thing.
Chapter 12 - "Professor Umbridge" - In which Fred and George advertise for volunteers to test their products, the trio discusses their schedules and the upcoming O.W.L.s, Harry has an outburst in Defense Against the Dark Arts, Umbridge assigns him detention for a week, and McGonagall warns him to keep his temper under control.