We've done all we can, studied, trained, prepared. The next move is Merula's.

All we can do is wait.

Leaves start to fall from trees. The air grows colder, promising snow soon. October fades into November, which in turn inches toward December.

Still, Merula does nothing.

Oh, she taunts us, of course, but nothing so serious that we can risk dueling her. Alana and I will not make ourselves the villains.

On the first day of December, Rowan asks me to play Gobstones in the courtyard. At first, I think it's an odd choice, with the weather growing colder. Then I realize that it's the perfect setting for a duel.

"Finch and I play Gobstones all the time on the farm," Rowan says. "I'm pretty good."

"I haven't played in years," I admit.

"Need a refresher on the rules?" Rowan asks as she sets out several small stone balls.

I nod, and Rowan continues, "We each start with fifteen Gobstones. The goal is to capture all of your opponent's stones. Each time a point is scored, the loser gets sprayed in the face."

"Sprayed with what?" I ask.

Rowan shrugs. "No one knows, but it smells disgusting!"

I laugh. "All right. Let's play."

We start the game, and I realize that I remember more of it than I thought. It's comforting, a reminder of the child I used to be.

"Did you see the Daily Prophet today?" Rowan asks.

I shake my head. "I don't get it."

"Merula's parents have been arrested," Rowan says.

"Really? Why?"

"The Ministry finally proved that they were Death Eaters. The article said that the Department of Magical Law Enforcement has been trying to convict them for years, but they could never get enough evidence."

I frown. "What changed?"

Rowan shrugs. "I don't know. The article didn't say."

"Are you talking about my parents?" We're interrupted by a familiar voice. Rowan and I get to our feet, facing Merula.

"Yes." There's no reason to lie. "So that's why you're always so angry? You were worried about your parents getting caught?"

"You know nothing about me. You think reading one article tells you anything?" Merula crosses her arms and glares at us.

I glare back. "Then why do you think you know anything about my brother?"

Merula smirks. "I know more than you can imagine."

I sigh in annoyance, but part of me can't help wondering if Merula really does know something I don't. "Why are you over here, anyway?"

"I learned a new spell. I thought you might like to see it." Merula lifts her wand, but it's not pointed at me, it's aimed at Rowan. "Flipendo!"

Rowan is thrown to the ground. I place myself in front of her. Rage rushes through me, and it's all I can do to keep myself from using a spell on Merula, but I stop myself. I have to let her hit me first, however annoying it may be.

A crowd has gathered around us, although no one seems interested in intervening. I spot Ben's terrified face in the crowd. Next to him, Alana gives me an encouraging nod.

Rowan gets to her feet and scrambles away, melting into the crowd. "Do you only make friends with cowards, Serantos?" Merula sneers, raising her wand again. "Flipendo!"

I fall to the ground, but quickly pick myself back up. "Rictusempra!"

Merula doubles over, laughing, as a jet of silver light hits her in the stomach. She still manages to attempt another Knockback Jinx, but it's weak, and I dodge it easily.

"Is that the only spell you know?" I ask derisively. "Expelliarmus!"

Red sparks fly from the end of my wand, pulling Merula's wand from her hand. It falls to the cobblestones. She looks at in shock, then straightens to face me. "How did you learn that spell already?" she asks in disbelief.

"Studying," I say. "I am a Ravenclaw, after all." I turn and walk away, hoping Merula won't try to jinx me while my back is turned.

"Don't walk away me! You haven't won!" Merula screams. "You're not better than me! You can't be better than me! I'm Merula Snyde, fourth-generation Slytherin! I do what I want when I want! I run this school! I-"

I keep walking all through Merula's tirade, but when she stops screaming, I turn around. Only one thing could have silenced her.

Sure enough, Professor Snape is standing behind her. Merula's back is towards me as she looks up at her head of house. Professor Snape's dark eyes are unforgiving as he looks down at her. I wonder if he's angry that she attacked me, or just angry that she got caught.

"Who cast the first spell in this duel?" Professor Snape asks, addressing the crowd around us. He can't trust us to tell the truth.

"Merula hit Rowan and Celena with Flipendo," a silver-haired Hufflepuff girl pipes up after a moment of silence.

Professor Snape nods curtly. "Thank you, Miss Lobosca."

Merula glares at the Hufflepuff. I hope whatever-her-name-is won't get in trouble for speaking up.

"Nevertheless, there will be consequences for both of you," Professor Snape continues, addressing me and Merula again. "The punishment I would suggest is... expulsion."

I gulp. I sneak a glance at Merula, and see my fear reflected in her eyes. Surely Professor Dumbledore won't expel us... right?

"You will meet me outside the headmaster's office after dinner to discuss the consequences of your actions," Professor Snape says before walking away. Merula watches him with a desperate and pleading look on her face.

As I watch his retreating back, I can't help but wonder... why outside Professor Dumbledore's office?

As the group around us disperses, Rowan, Ben, and Alana join me. I look for Lobosca. I want to thank her for telling Professor Snape what happened, and offer her help if Merula comes after her. But she's already gone.

"Great job, Celena!" Rowan says excitedly. "Merula certainly won't be coming after us again for a long time."

"Thanks," I mumble, but part of me doesn't agree with Rowan. Yes, Merula will lay low for a while, but once her dignity has recovered and her anger has had time to ferment... then she'll want revenge.

"I was terrified the whole time," Ben confesses. "Especially when Merula hit you with the Knockback Jinx. But you just got up and hit her back."

Alana simply nods, apparently deciding that Rowan and Ben have said everything.

"Come on." Rowan loops her arm through mine and starts pulling me away. "We still have homework to do."

I laugh. "Only you could think of homework at a time like this, Rowan."

Rowan shrugs.

The corridor outside Professor Dumbledore's office is freezing, even for December. I wish I'd worn something warmer.

Professor Snape and Merula haven't arrived yet, but I spot a blonde girl standing at the end of the corridor. I know her name. It's one of the few I can remember. Penny Haywood, Hufflepuff and the most popular girl in our year.

Penny spots me and walks quickly to where I'm standing. "Celena!" she exclaims warmly as if we're friends, when in fact we've never spoken.

"You know who I am?" I ask in surprise. I try to remember if she was in the crowd when I dueled Merula.

"Does that surprise you?" Penny asks.

"Yes. You're Penny Haywood, and I'm... me. I'm not popular." Well-known, yes, but popular? No.

"I disagree," Penny says. "You stood up to Merula Snyde when no one else would. Everyone respects you for that... except for maybe a couple of the Slytherins."

"Well, umm... thank you."

"I also wanted to say that I'm pretty good with potions, so I can help you if you ever need it." Does she think that I'm struggling in potions? Because I'm not.

"Thank you," I say again. Please leave. This conversation is making me so nervous.

Penny leaves, but I'm not alone for long. Professor Snape arrives, followed by Merula.

"Now that Miss Snyde is here, we can discuss your punishment," Professor Snape says. "I still believe that expulsion is the most logical choice."

I can feel my heart pounding in my chest. Merula lets out an odd sort of whimper. Professor Snape ignores her and continues, "However, the headmaster is illogical and believes that expulsion isn't fair in this case. Miss Snyde, you will report to the kitchens every day before breakfast for the next two weeks. Miss Serantos, Hagrid has asked for your help. You will meet him at his hut tomorrow after classes are over."

I wonder why we weren't given the same detention. Maybe we just can't be trusted together.

"Meow." I look down to see a kitten sitting near my feet. Her name is Mrs. Norris, and she belongs to Filch. There are rumors that he's training her to identify troublemakers. If she found us, he's training her well.

"Excuse me," Professor Snape says, looking down at Mrs. Norris. "Filch and I have business to attend to."

He follows Mrs. Norris as she pads down the corridor. I realize that they're walking in the direction of where I felt that abnormal cold a few weeks ago.

Merula starts following them, so I follow her. I'm curious about what's happening.

Merula crouches behind a suit of armor not far from where Professor Snape has joined Filch. I find a suit a bit farther back, just within earshot.

"Only me and Mrs. Norris saw the ice, sir." Filch picks up Mrs. Norris and pets her head lovingly. "Was going to report the incident to the Headmaster, I was."

"I will take care of that," Professor Snape says. "This may have to do with the Serantos situation."

I frown. Why would Professor Snape say my last name unless he was talking about... the Cursed Vaults?

"Is it true that the vaults are full of gold and prophecies from before Hogwarts existed?" Filch asks. "And that's why the Serantos boy lost his mind trying to find them?"

"Do not concern yourself with what is inside the vaults," Professor Snape snaps. "Worry about keeping the students out. Lock this door and keep it guarded."

I tiptoe away, careful not to be seen. A thousand questions whirl through my brain, none of them with answers. What's inside the locked room? Why were the vaults built, and what do they contain?

And when Professor Snape said my last name, was he referring to Jacob... or me?