Has Hermione Made A New Friend Or Enemy?

Hermione Granger starts guarding the outside of Hogwarts, because she's heard of a mysterious figure, who has been roaming around Hogwarts, during the night. The mysterious figure turns out to be Luna Lovegood and Hermione's not sure if Luna's an ally or a threat, to the future of Hogwarts. Meanwhile, Ron Weasley hopes he can impress Hermione, while Voldemort has a plan of his own.