The next morning, a Sunday, Leo and Marisa were in the common room playing Exploding Snap with Theo, Daphne and Tracey and discussing the latest disturbing rumours.
"Did you hear who was attacked?" asked Marisa.
"Gryffindor first-year. Colin Creevey. Mean anything to you?" Theo tapped the pile of cards in front of him with his wand and watched as they lit up a silvery-grey colour.
She thought for a moment. "Wasn't he the one who was always taking pictures of Potter?"
Leo slammed his wand down on her pile: she had been distracted and hadn't noticed the red six she had, the same as the face-up card.
Theo nodded. "There's a rumour going around that Potter's the Heir of Slytherin, because of that."
"But he's in Gryffindor!" said Tracey. "He can't possibly be Slytherin's heir…"
"It makes no sense!" agreed Daphne.
"How many cards do I owe you?" asked Marisa, sighing.
"I don't know…" Leo said thoughtfully, sensing the eyes of the group on him. "It's possible… I wouldn't think it likely but it could be that he's pretending to be incompetent very, very well… Oh, and five."
"Who do you think it is?" asked Marisa, counting out the top five cards from her pile and handing them over to Leo. "It's almost certainly a Slytherin, right…?"
"Don't see why it matters to us," Theo said. "We're safe. None of us Slytherins are muggle-born."
There was a very, very awkward silence. Everyone looked at Marisa, who glared at Theo and said absolutely nothing, although her eyes were clearly saying "If you don't apologise at once, something very unpleasant will happen to you."
Theo's pile of cards exploded right underneath his slightly sheepish face.