The head of the school turns out to have been working with Voldemort all along, hoping to corrupt the pupils under his watch.
Snape reveals that HE is actually Harry's father, and his, ahem, ambivalent behavior stems from guilt over having betrayed his friend (Harry's now-foster father) with his affair with his friend's wife and not being able to tell Harry the truth.
Ron turns to be more of a playa than originally thought, narrowly avoids getting dumped/magically castrated by H (turns out you really, REALLY don't want to cheat on a witch)
Ginny turns out to be a Skrull.
And yes all of the above is complete and total bullshit. Or is it...
Snape reveals that HE is actually Harry's father, and his, ahem, ambivalent behavior stems from guilt over having betrayed his friend (Harry's now-foster father) with his affair with his friend's wife and not being able to tell Harry the truth.
Ron turns to be more of a playa than originally thought, narrowly avoids getting dumped/magically castrated by H (turns out you really, REALLY don't want to cheat on a witch)
Ginny turns out to be a Skrull.
And yes all of the above is complete and total bullshit. Or is it...