That evening in the Slytherin common room, the group split up. Tracey was tired and went to get an early night, while Theo and Daphne continued their earlier Exploding Snap tournament.

"You joining us, Leo?" asked Theo.

"No, I was thinking of going…" he glanced at Marisa, "somewhere else."

Marisa picked up on his hidden meaning immediately and followed him out of the common room and seven floors up. They narrowly avoided Filch by slipping down a secret passageway on the fourth floor and eventually, nerves on edge, they reached the picture of Barnabas the Barmy.

We need a place to relax and talk… Marisa thought as she paced back and forth until the door handle appeared in the wall. Then she grabbed it and pulled it outwards.

"Come on in," she said, gesturing theatrically to the door.

"Ladies first," replied Leo, making the same gesture.

Marisa rolled her eyes. "No, after you!"

"Oh, for goodness' sake, this is pathetic!" said Leo and went through the door.

Marisa followed him through and saw two massive beanbags, one green and one silver. Smiling, she flopped down on the green one and Leo claimed the silver.

"So," asked Leo, "anything happen?"

"Nothing I haven't already told you."

"Any thoughts on codenames? I mean, I'm obviously Snow Leopard – "

"Why?"

"Because I like the animal, and also because I've had a couple of dreams with one in."

"Oh."

"I was thinking of Lioness for you, because of your hair. How does that sound?"

"Mm… it's alright, but not really me. I prefer to work alone. Can I be Tigress instead?"

"I like the sound of that," said Leo. "My little tigress."

Marisa curled her fingers into claws and raked the air playfully. "I'm not your tigress," she said, glaring at him, "and I'm not a tame cat!"

The reference was lost on Leo, who of course knew no Muggle literature. Marisa smirked.

"Draco…" said Leo suddenly, then hesitated.

"What about your idiotic adopted brother?"

"He said something funny…"

"Just spit it out, won't you!"

"He said… you wouldn't be around much longer. Because my – his dad had done something that was going to kill Muggle-borns."

Marisa raised one eyebrow. "Really? In Hogwarts? Because that doesn't exactly seem very likely!"

"I don't know the details. I don't think Draco did."

"Well," said Marisa, "I'd like to see the thing that could stop me."

"My thoughts exactly," said Leo with a slight smile. "Especially with me backing you up."

"I do not need your help," Marisa insisted, aiming a playful blow with her left hand.

Leo ducked and then stood up, aiming a Jelly-Legs Jinx at Marisa, who wobbled as her legs gave out beneath her.

She drew her wand and hesitated before twisting it in the shape of a leaf. "Rictumsempra!"

Leo tried to dodge but was too slow: Marisa's Tickling Charm hit him directly in the stomach. He burst out laughing as he collapsed to the ground. "No – " he gasped between ridiculous giggles. "Stop – "

Marisa smirked. "Do you concede?" she asked, keeping her wand firmly trained on Leo.

Leo hesitated, laughing. He looked about to admit defeat, but then he grabbed his wand from where he'd dropped it and managed to choke out: "Melofors!"

Marisa gasped. She couldn't see anything except orange and the air around her smelt of pumpkin. Her entire head had been encased in a pumpkin.

She couldn't move her wand or the Tickling Charm would be dispelled, so she reached up with her left hand and lifted it off her head.

"Locomotor Mortis!"

Still preoccupied with the pumpkin, Marisa was unable to dodge Leo's Leg-Locker Curse and her legs slapped together. Furious now, she threw the pumpkin at him with all the force that she could muster.

He rolled out of the way and Marisa kept her wand firmly trained on him. She wouldn't be able to dodge without the use of her legs if he threw another curse at her, which meant she had to do something quickly.

Taking a deep breath, she dispelled her Tickling Charm and immediately yelled "Petrificus Totalus!" It was extremely clunky, yes, but it was the only spell she knew that could stop Leo completely and certainly.

His eyes widened and he tried to avoid her spell, but was too late: it hit him and his limbs snapped together.

"I win!" said Marisa triumphantly. That was when she remembered that she didn't actually know the counter-charm.