The air elementals, which have shown up in other DWJ novels (notably The Merlin Conspiracy) are secondary characters in this one, but they're pretty charming. First-year student Olga spent much of her youth talking to them and enjoying their friendship, but after a severe punishment for some transgression, she can't see them any more, which makes her very lonely and sad.
What seems like a calamity happens to her early in this novel, and she runs away to the roof of a tall building to cry about it, since she doesn't want to let anyone see her lose her cool emotionless facade. However, this turns out to be the key to being able to connect with the elementals, and she's thrilled to find they are all around her and glad to have her back as their friend.
Later in the novel another group of air elementals turn out to be the key to saving the lives of several of the wizards & trainee wizards, so it's a fortuitous wind that blows everybody a great deal of good.