"What the bloody hell are you doing here?" Ron yelped.
"I should think it would be obvious, Weasley," said Malfoy, setting the broom down. "I'm cutting myself in."
"You're doing what?!"
"Cutting myself in, of course. Infinite life, infinite wealth? Seems like you can afford to split infinity four ways, instead of three!"
"You're after the Stone!" Ron said.
Hermione didn't wait for his answer. She pulled out her wand and shouted "Petrificus Totalus!"
"Protego," said Malfoy carelessly. The curse rebounded off of his wand and barrelled back toward Hermione, who only just jumped out of the way in time.
"Locomotor Mortis!" said Ron.
"Protego," said Malfoy. Ron's jinx flew up into the air and scattered a handful of the brightly-coloured keys.
"Petrificus Totalus Tria!" Hermione had got her balance back.
"Protego Maxima!"
Hermione's spell exploded in midair, about a foot from Malfoy. The air around him sort of shimmered, and he smiled.
"I expect the mudblood knows what that does," he said, looking at Hermione.
Harry didn't know what mudblood meant, but when Malfoy said it, Ron choked. "You horrible, evil, vile, loathsome little slug!" he shouted.
"What's a mudblood?" asked Harry.
"Don't say that word! Slugul…"
"Don't, Ron," said Hermione. "It won't do any good. He's got a protection spell up."
"A which?" asked Harry.
"A sort of magical barrier. A force-field."
"Like Invisible Woman?"
"It means you can't hex me," said Malfoy, twirling his wand. "Now, maybe we can have a civil discussion."
"We have nothing to discuss with you, Malfoy," said Ron.
"Oh, I think you do. Because, well…I have the key, and you can't get at it."
"We'll figure out another way to get through the door," said Ron.
"Don't be stupid, Weasley. It's a Bluebeard lock, or didn't you hear me?"
"What's a Bluebeard lock?" asked Harry.
"It's a lock charmed so that nothing but the key can open it," said Hermione. "Bluebeard was a powerful dark sorcerer with a lot of secrets to hide."
"A Slytherin," Ron added.
"All right, and Malfoy has the key. Or he says he does."
"It does look right," said Ron. "It's big and silver and has blue wings. Dad told me once that stuff having to do with Bluebeard usually turns blue if you try to enchant it; Bluebeard liked blue…"
"But I can see four silver blue-winged keys from here," said Harry.
"Well, there's one way to find out," said Hermione. "Non-harmful spells can go through a Protego Maxima barrier, so…" She pointed her wand at Malfoy's hand and said clearly, "Sera Revelio." A bolt of white light shot from her wand, bounced off the key, turned blue, and shot straight for the lock, which then also glowed blue.
"That's definitely the right key," said Hermione.
"Right, then," said Harry, unwilling to waste any more time. "What do you want, Malfoy?"
"I told you. I want to be cut in."
"Not possible. We're trying to protect the Stone, not steal it."
"And how are you planning to protect the Stone, may I ask?"
The three Gryffindors looked at each other.
"By stealing it," said Harry.
"As I thought. Well, if you're going to steal it anyway, you might as well use it. And if you're going to use it, you might as well cut me in. Besides, I could be useful. I mean, if this is the first chamber, imagine what must be further on. You'll do better with four than with three."
"Much as I hate to say it," said Harry, "that's actually a good point."
"What?" yelped Ron.
"Not the bit about using it, the bit about him being useful…well, you have to admit he's a talented wizard," said Harry, looking at Hermione. "And we haven't got much time. And he's got the key." He looked back at Malfoy. "We can discuss using it at a later date, Malfoy," he said. "Right now let's focus on getting it; any minute now a man could come through there who could blow four first-years into oblivion if he wanted, and I don't think you want him getting the Stone any more than we do."
"Oh, yes, I heard you talking before. Coach Potter." Malfoy made a face. "That would be unfortunate in the extreme. The man's insufferable."
"You only think that because he criticised your broom-handling," said Ron.
"So, Malfoy, we'll make a deal. We all want to keep Potter from getting the Stone. So we all get the Stone, together, as amicably as possible, and then we'll decide what to do with it."
"No good," said Ron. "He'll kill us all when we get to the final test and run off with the Stone."
"All right, we'll decide what to do with it when we all get out, safe and sound," said Harry. "And no one's going to kill or, or incapacitate anyone else. At all."
"What happens if one of us dies through no fault of any of the rest of us?" Malfoy wanted to know.
"That's not going to happen," said Harry through his teeth. "Do we have a deal or don't we?"
Malfoy shrugged. "I suppose so."
"Not good enough, Malfoy!" said Ron.
"Well, what do you want me to do? Perform an Unbreakable Vow?"
"Actually…"
"We don't have time for that," said Harry. "Just give us your word. As a…as a…Malfoy."
His shot in the dark seemed to have hit a sensitive spot. Malfoy started as though he'd been given an electric shock and stood up straighter. He and Harry stared at each other for a long moment. Finally, he gave a curt nod.
"Fine," he said. "On my honour as a Malfoy."
"I'm not sure we should trust him," said Hermione.
"Be quiet, Hermione," said Ron.
Malfoy held up a hand. "But I have terms, as well."
"Oh my god," muttered Harry. "What?"
"Well, you can't cut me off or cut me out or leave me anywhere, and if we get through you have to actually listen to my point of view while we're trying to decide what to do. I get at least as much say in it as you three."
"Fine," said Harry. "Hurry up."
"That's not good enough, Snape," echoed Malfoy. "You have to give me your word."
"Are you serious?"
Malfoy nodded. "Your word, on something that matters."
Harry sighed.
"I swear," he said, "on my mother. I won't abandon you, and I'll listen to you when we're through. Now come on."
Malfoy studied Harry for a moment, and then flicked his wand. "Finite Incantatem," he said; the air in front of him shimmered, and he stepped forward, holding out the key. Ron seized it, as if afraid Malfoy might change his mind at the last moment, and gave it to Harry, who stuffed it into the lock and turned—it worked. The moment the lock had clicked open, the key took flight again, looking slightly battered.
"Ready?" Harry asked. The other three nodded, and Harry pushed the door open.