Lily stands in the hallway outside the Headmaster's Office, clutching an envelope and telling herself to stop being ridiculous.

It's just tea.

Of course, it's tea with the Headmaster on the occasion of her seventeenth birthday, but it's still just tea.

Intimidating tea, but tea, none the less.

"Excuse me," Lily says, to the gargoyle in the hallway, holding out the invitation. "I think the Headmaster is expecting me."

There's a moment, and then the gargoyle reveals a moving spiral staircase leading up to Professor Dumbledore's office.

It has been what must be considered a perfectly lovely weekend. And even the prospect of having to return to classes in the morning can't dim anyone's good mood this evening.

It's time for the annual Hallowe'en feast.

The Great Hall is, of course, decorated fantastically, with great swooping clouds of fluttering bats, flaming orange streamers that twist and wind their way around the ceiling in ever-changing patterns, and jack-o-lanterns. Dozens and dozens of jack-o-lanterns, bobbing above the four House tables, candles flickering atmospherically.

The first years sitting just down the table from them stare around, wide-eyed and gaping, nudging each other to point out this detail or that. Lily smiles, remembering when the Great Hall was not only impressive but new, and things like Hallowe'en were times to be wonderstruck.

She turns to Mary, sitting next to her, the only other Muggleborn Gryffindor girl in their year. "That used to be us, you know," she says, nodding towards the younger students.

Mary doesn't answer. She's busy staring, wide-eyed and gaping, at the carved pumpkin bobbing in front of them.

"Mary?" Lily says. "Everything all right?"

"Look," Mary says. "Look at the pumpkin."

Lily looks up, briefly, and turns back to Mary, "Yes, I know, it's ... "

And then her brain catches up with her eyes, and she looks back up at the glowing, candle-illuminated face that is unmistakeably Professor McGonagall, carved into an orange squash.

"Oh ... my ... "

Lily turns quickly to look at the other pumpkins. From where she's sitting, she can make out Flitwick (slowly revolving, a few yards away and just above Cliona and Fenton), and Slughorn (slightly off-kilter, floating above the Hufflepuff behind her), and even Grindstaff (scowling down on the first years, looking not at all amused about having been rendered in squash).

"It's the professors," Lily says. "They're all ... they're all the professors."

"I know," Mary says.

A pumpkin carved to look like Dumbledore goes careening cheerfully down the length of the table, and the other pumpkins move respectfully out of the headmaster's way.

Mary and Lily look at each other for a moment, and then they start to laugh.

Maybe Hallowe'en still has a little wonder to strike after all.

Lily is sitting in an otherwise deserted Great Hall, halfway down the Gryffindor table, reading A Standard Book of Spells, Grade Five.

With OWLs coming up, sometimes it feels like all she ever does is study. Ever since they got back from Easter break, they're harder to escape, to avoid, to think of as later.

She's reviewing switching spells when a shadow falls across the page and she looks up to see Professor Dumbledore.

"Miss Evans," he says, "may I join you? There's a matter we should discuss."

"Oh, um, of course, Professor," Lily says, closing her book. "What is it?"

Professor Dumbledore sits down next to her. "I have for some time been concerned about the relationship between your esteemed House of Gryffindor and that of Slytherin. And I fear the animosity is growing worse of late."

Lily nods. "I would have to agree with you."

"I'm so glad that you see it that way," Professor Dumbledore says. "Unity among our Houses is never so important as it is at times of challenge and threat, like those we face now."

Lily nods again.

"So there is something I need for you to do, Miss Evans. You may, in fact, be the only one who can."

"Of course," Lily says. "What do you need me to do?"

"You will marry Severus Snape."

Lily almost falls off her seat.

"Excuse me, Professor? I'm sorry, did you say you want me to marry Sev?"

"Yes. Thereby uniting the Houses of Godric Gryffindor and Salazar Slytherin and ending this strife."

"But I can't marry Severus. I … I can't," Lily says.

"Of course you can," Professor Dumbledore says, standing and starting for the platform at the far end of the hall, where the professors sit during meals. "It's all arranged."

Lily grabs her book and follows him. "It can't be all arranged. Don't I have any say in – "

Lily stops, because suddenly her robes are too long and dragging on the floor. And they're not robes, but a ridiculously long white dress with a train and trailing sleeves and a heavy gold belt. There are flowers braided into her hair.

And the room is no longer empty, but full of people in dresses like hers and silly hats and doublets and chain mail. The House tables have vanished, and the end of the room is now a dais holding two elaborately carved thrones. One is empty. Severus is sitting in the other, wearing a long green cape and a silver crown, with a sword at his waist.

Lily tightens her grip on A Standard Book of Spells, Grade Five.

Severus stands, and Dumbledore actually bows to him. "My lord Arthur," he says, "may I present the Lady Guinevere?"

"We welcome you to Camelot," Severus/Arthur says.

Lily sweeps the kind of curtsey she knows should leave her sprawled in the floor.

And when she straightens back up, she's somehow up on the dais in front of the thrones, facing a group of four knights.

Severus/Arthur beckons, and one of them steps forward. He wears a red and gold surcoat over very shiny chain mail. He also has untidy black hair and glasses.

"Sir Lancelot du Lac," Severus/Arthur says. "My bravest and most trusted knight."

No. Way.

Potter/Lancelot bows over her hand, brushing his lips across the back of it. And then raises his eyes to hers and smiles an I am going to get you in so much trouble and you're going to love every second of it kind of smile at her.

Lily drops A Standard Book of Spells, Grade Five, which it hits the floor with a THUD and she …

… jerks awake with a start, utterly disoriented for a second.

And then realizes that she has fallen asleep at the end of the universe.

Lily looks down and sees The Once and Future King on the floor, where it must have landed after it slid out of her lap.

Lily makes a mental note: henceforth, Arthurian Legend is to be avoided at times of stress.