The war was years ago, and Draco's life has calmed down. When he first gets a present and 'love-note', he's rather flattered. His feelings quickly turn to horror as the gifts take on a rather unhealthier tone.
Harry has been abused by the Dursleys all his life. Between Hagrid's visit in July, and his leaving for Hogwarts, it gets worse, and one of Harry's eyes is severely damaged. As it heals itself, it seems to change, and Harry finds he can 'see' magic.
When Hermione manages to get Harry to learn another language with her, the only perk he sees is that he can at least insult Malfoy in front of some professors. But some other things are more easily said when no one else can understand you.
Lucius, Antonin, and Rodolphus make a band. A Death Eater band, in fact.
Harry is plagued by feelings of uneasiness as he returns to Hogwarts. Soon, he begins to see a slender, faceless man, and fears he is losing his mind. I blame the wait between Marble Hornets entries for this.