The book starts out, like the first, at Harry's aunt and uncle's house on Privet Drive. They are still horrible people, but since they're afraid Harry will do magic on them, it is perhaps not quite as unbearable as before; and this summer, he had his friends from school to keep in touch with. Or so he thought. He hasn't actually heard from any of them all summer, and Harry's uncle never lets him send his owl out, so he hasn't been able to write either. He also can't study, since all his school stuff is locked up in the cupboard that used to be his bedroom. Being that he is around twelve years old, though, I seriously doubt he would have been spending his time actually studying, but I guess you never know.
Anyway, so one evening, the Dursleys (that is, his aunt and uncle) have Harry shut up in his room while they have company over, when a house elf shows up and gives Harry some cryptic warnings about how he shouldn't go back to school, because bad things are going to happen there. Obviously, this house elf was not aware of the events of the previous year, or he would have realized that Harry has been there and done that as far as "bad things" are concerned.

