While Hogwarts' newly minted graduates are departing for the train platform in the usual first-year boats, the rest of the school will be heading toward the Hogwarts Express via carriage.

These are the same carriages that brought you, with the obvious exception of the first years (who are henceforth known as second years), to the school on your first day. They are round, black, and seat about four students.

The carriages also appear to move along on their own, with an invisible something inside the harnesses...