• Luna and Snape land outside Grimmauld Place.

"They can't know I helped you," he said in a low voice.

Luna looked up at him bewildered. "Why not? If you're on our side —"

"We can't risk the Dark Lord getting into Harry's mind," Snape pointed out. "So they can't know. Not yet."

"Okay," Luna agreed.

"Here." Snape removed a vial with a clear liquid inside.

"What is it?"

"It's my memories. Give them to Harry when the time comes." And without waiting for her to respond, he was gone.

• Luna persuades Sirius and Remus to bring Xenophilius to Grimmauld Place so the Death Eaters can't take out their anger on him.

• Luna mentions how Xenophilius had been trying to recreate the lost diadem of Ravenclaw, which makes Harry think if that was another Horcrux out there.

• So they sneak into Hogwarts and into the Room of Requirements with Neville's help (I'm not sure on the details).

• (Also, I have no idea what time of year it is, but let's just say that whatever the corresponding events from canon are moved up sooner.)

• Much of the D.A. are there.

• Before Harry can even think to ask about Fred, Fred arrives (along with several other people).

• "Hello, Harry! Long time no s —" Harry leaps into his arms.

• "This isn't the time to make out." / "Hush, Sirius, give them a moment."

• Harry, Fred, and Luna go to the Ravenclaw Tower, Alecto's there, yada yada yada, you already met Bill the drill.

I almost forgot about Ravenclaw's diadem. And I'm pretty sure I didn't have it brought up earlier, but if I did, whoops.