"No way," said Calvin, tossing his papers onto the library table and sitting down with a 'thump'.

"No way what?" asked Sara, busy making a paper airplane. The fun thing about paper airplanes in the wizarding world, Erin thought, was that they could be spelled to fly for incredibly long distances.

"It can't be April already."

Erin looked out the window. The wet and dripping landscape was quite pretty, despite the clouded sky above it. April showers bring May flowers. She shook her head to clear her mind of the rhyme and turned back to her Potions homework. Not that she really needed to do it; Severus would have given her free points any day. But she preferred to earn her own grades. She'd even gotten into the habit of checking her tests when she got them back, to make sure her guardian hadn't "missed" a few wrong answers. Erin grinned. She really was beginning to love him, though. It was funny. He wasn't a pleasant person to be around, by any means, but - she'd rather have him at her back than anybody else. She trusted him.

A crumpled ball of parchment smacked Erin in the head. She glared at Calvin, who grinned. Blaise put down her book and shook her head at their antics, then turned firmly and pinned Erin with her fierce gaze. Erin sighed. She knew exactly what was coming.

"Erin, we need to talk about Fallan," said Blaise. Erin could have spoken the words with her.

"I don't see what there is to worry about," said Erin, deliberately perusing her notes. Blaise yanked them out of her reach.

"Erin, if you're not careful, he'll Challenge you."

Erin frowned. "I've heard that before. What is Challenging anyway?"

This time, Calvin spoke. "It's a very serious Slytherin ritual, installed by Salazar himself. It was used to prevent major infighting."

"How?" asked Erin, suddenly intrigued. Sara also looked up.

Calvin continued on quietly. "It's - sort of hard to explain. A lot of us are obsessed with power." Erin's gaze dropped, remembering her episode with the mirror. Calvin, not noticing, continued. "So it's only natural that there would be a lot of power struggles. Who was Head Boy or Head Girl, who was the "royalty", all of these things were continually fought over."

"But most importantly," interrupted Sara, "so was the Head of House."

"I don't understand," said Erin.

"Slytherin isn't like the other houses," said Blaise. "Our Head's power depends on the students, especially with those students whom he or she favors."

"The Head is constantly making alliances to stay in power," said Calvin. "We all are. So Slytherin introduced the Challenge as a way to settle all of it once and for all."

Calvin paused for breath. "When one student Challenges another, they have a duel, which is refereed by a Hufflepuff, so it'll be fair. Whichever is stronger wins, and after that, nobody else can Challenge the student who was Challenged. It's a one time deal."

Erin frowned. "I still don't see how that involves the Head."

"Students can't challenge the Head directly," said Sara. "But they can challenge the Head's favorites. If the favorite loses, so does the Head."

"So if Fallan Challenges you," said Blaise sternly, "and you lose, so will Snape. And Slytherin will go over to Voldemort."

There was a pause. "Oh," said Erin.

"I think," said Calvin, "you'd better ask Snape for dueling lessons."

"But why would Fallan Challenge me?" asked Erin plaintively.

"Because you're the most powerful one," said Sara matter of factly. "You're You-Know-Who's daughter. Like it or not, you're the leader. And that's what Fallan wants."

Calvin snorted. "Stupid Durmstrangs."

"Dueling lessons," said Blaise flatly. "And quickly."

Severus met Avery near the edge of the Dark Forest. "Well?" he asked.

Avery drew off his black Death Eater's mask. "Just got back from a meeting."

"I could tell that."

"Don't get sarcastic now, Sev. Something big's going to happen."

Severus stiffened. "What?"

"He didn't say exactly. Seemed awfully pleased, though. I overheard him talking to Lucius. Something about Hogwarts and Slytherin and Lucius' son."

Severus sighed. "He's going to try and bring Slytherin over."

"Like their going to need a lot of convincing," said Avery glumly. "Don't you remember us? The Cobras? Lucius, you, me - "

"Yeah," said Severus softly. Of course he remembered those days. Constantly pulling strings, experimenting with black magic, half-drunk on their own power. He hadn't hesitated to join Voldemort - not until Dumbledore had called his debt and asked him to be a spy.

"They need a leader," said Avery, gazing up at the stars. "No offense or anything, but you being the Head isn't enough. They need somebody strong who's against Voldemort."

"I've tried," said Severus. "Erin won't take it."

"Phoenix boogies. There's nobody else who could do it."

"She hates the politics."

"Ptomely's toenails, what kind of Slytherin is she?"

"I haven't the faintest idea," said Severus, irritated both with Avery and with his daughter.

Avery sensed the irritation and backed off. "Okay, okay. What do you need me to look for now?"

Severus responded promptly; he'd already thought his plan out far ahead. "Give me an opportunity to nail Lucius. He's one of the strongest."

"What do you have in mind?"

"A party, a feast, something busy." Severus' face darkened.

Avery looked at him closely. "Don't let revenge get in the way," he said softly.

Severus twitched up in a ghastly smile. "Oh, no. Revenge isn't going to get in the way at all."