As they enter the castle, [Harry] and [Hermione] are called away by [Professor McGonagall]. She and [Madam Pomfrey] make sure Harry is alright after the [dementor] attack, and then after McGonagall has a brief private conversation with Hermione, they all make their way back to the [Great Hall] together.
On the Hogwarts Express
A frenzied breakfast ends with the [Weasleys], [Harry], and [Hermione] taking [Ministry cars] to [Kings Cross Station], while Harry continues to think about [Sirius Black] and [Ron] protects [Scabbers] from [Crookshanks].
[Arthur Weasley] and [Harry] stroll onto [platform nine and three-quarters], and are soon followed by the rest of the family. Before saying goodbye, though, [Harry] admits to [Arthur] that he'd overheard his conversation about [Sirius Black], and runs off to catch the train as it pulls out of the station.
[Harry] pulls [Ron] and [Hermione] into a private compartment, with only a sleeping [Professor Lupin] already there, and tells them about how [Sirius Black] is after him. After a brief interruption from Harry's [Sneakoscope], they discuss instead the fact that Harry won't be able to visit [Hogsmeade].
As the [Hogwarts Express] continues on, the [witch with the food cart] comes by and is followed shortly by [Malfoy], [Crabbe], and [Goyle], though they decide it foolish to attack [Harry] with [Professor Lupin] in the compartment.
The Affects of the Dementor
The [Hogwarts Express] suddenly stops and goes dark, and after some apprehensive moments in which [Ginny] and [Neville] arrive, a [dementor] comes into [Harry]'s compartment - causing Harry to hear a scream and black out.
[Harry] wakes up to learn that [Professor Lupin] had made the [dementor] go away, and that [Ginny] too had been extremely upset by the creature.
[Harry], [Ron], and [Hermione] make their way toward [Hogwarts], despite a brief moment where [Malfoy] makes fun of Harry for fainting.
The feast begins with announcements from [Dumbledore]: the [dementors] will be guarding [Hogwarts] until further notice, [Remus Lupin] will be the new [Defence Against the Dark Arts] professor, and [Rubeus Hagrid] will be taking over [Care of Magical Creatures].
[Harry], [Ron], and [Hermione] enjoy the welcoming feast, and then congratulate [Hagrid] on his new position as they make their way up to [Gryffindor Tower] and to bed.