JAMES POTTER AND THE VAULT OF DESTINIES

       'Because whatever it was,' Zane went on, realization dawning on him, 'it would be way too magical to leave in his offices! People would sense something that powerful, especially if it came from another dimension!'

       Straidthwait leaned back again, using his index finger to tap the side of where his nose used to be. 'My thoughts precisely,' he concurred. 'Because there is one thing that is for certain: whatever this alleged pan- dimensional key may have been, Magnussen was not carrying it on his person that night. If so, he'd never have been able to escape unnoticed. He may well have been on his way to the Nexus Curtain, if such a thing truly exists, but if he was… then he was going to retrieve the key first.'

       'So,' Ralph announced after a meaningful pause, 'if we can somehow find a way to follow Magnussen… we can find the key.'

       'Find the key,' Straidthwait mused, 'and I expect the Nexus Curtain will reveal itself.'

       Zane shook his head. 'But how do we follow someone whose been gone for a century and a half?'

       'Mercy, young man, you say you're a member of Zombie House,' Straidthwait said, nodding at Zane. 'I am surprised you haven't already divined the answer to that question.'

       'Give me a second, already,' Zane replied, piqued. 'I've only had a minute to think about it.'

'And therein lies the solution, my friend.'

       'How's that?' James asked, somewhat frustrated. 'Time is exactly our problem. Like, a hundred and fifty years worth of it.'

Straidthwait sighed wearily. 'No, boy. Time is your solution. Have you forgotten,' he said, leaning slightly forward, his remaining eye twinkling, 'that this school is, in essence, one gigantic time machine?'

       Shocked, the three boys looked at one another, their eyes widening slowly. In the dark heat of the mausoleum, Straidthwait chuckled hollowly.

       In the wake of the interview with Charles Straidthwait, James had gotten a vague idea of what they needed to do next. Unfortunately, with the Christmas holiday approaching, bringing with it a wave of midterm examinations, there was very little freedom to plan any time-traveling adventures in pursuit of the long lost Ignatius Magnussen.

       'Tell me again why, exactly, you are planning to do this,' Rose asked disapprovingly from the Shard as James and Ralph practiced Shield Charms for the next day's Cursology exam. 'Pardon me for saying that it all seems a tad complicated and ridiculous.'

       'It's simple,' Ralph said, his tone of voice implying that he didn't quite understand the plan himself. 'Whoever broke into the Vault of Destinies stole a crimson thread from some other dimension's version of the Loom. Normally, something that massively magical would be easy to track down since it'd be sending out waves of power like some kind of siren. For some reason, though, nobody's picked up the slightest trace of it, not even James' dad and the local police. Zane thinks that that's because the people that stole the thread used it as a key to open the Nexus Curtain and hide it in the World Between the Worlds, which is sort of like a hub that connects all the dimensions.'

       'Right,' James agreed. 'That's the only way the thieves could escape without being traced. We need to follow Magnussen into the past to nick his key to the Nexus Curtain. If we can figure out how to get through to the World Between the Worlds, then we can try to see who really did steal the thread and prove that Petra isn't really involved.'

       'And what will you do if this is all bilge and Morganstern really is the culprit?' Scorpius scowled from his side of the Shard. James had prepared himself for such a question.

       'She's not, but even if she is, this is what friends do. She says she's innocent, and we're doing what we can to prove her case.'

       Scorpius narrowed his eyes and smirked slightly. 'So you're doing this for friendship, are you?'

       'You can't just rush into something like that anyway,' Rose interrupted. 'Time traveling is extremely dangerous business. You could do far more harm than good.'

       James sighed and rolled his eyes. He hadn't wanted to tell Rose and Scorpius about it at all, but Ralph, being his typical self, had been unable to resist telling them all about the midnight conversation with the undead Professor Straidthwait.

       'We know, Rose,' James proclaimed, trying to head her off. 'It's Technomancy one-oh-one, all right? Accidentally step on a bug in the past and you change the whole present. Blah, blah, blah.'

       'But really, how bad can it be?' Ralph commented, sitting down on his bed. 'I mean, James zapped himself a thousand years into the past and butted heads with Salazar Slytherin. He changed loads of things, but everything still seems just fine here in the present day.'

       Rose shook her head in annoyance. 'One,' she said, stabbing a finger into the air, 'we don't know that James didn't change the present since everything we know is based on the history he affected. It may be that there were changes, but they weren't terribly important. Two,' she stuck a second finger into the air, 'just because James got lucky once, doesn't mean the three of you won't bollix things up royally this time out.'

       'We'll be careful, Rose,' James insisted, lowering his wand and turning toward the Shard. 'I know you're jealous because you can't come along with us and all, but that doesn't mean you have to try to scare us out of doing it.'

       'That's not it at all,' Rose fumed, crossing her arms and flopping back against the sofa in the Gryffindor common room. Next to her, Scorpius grinned a little crookedly, apparently seeing the truth in James' words. 'I'm smarter than you,' Rose went on sulkily. 'I know how much damage you lot can do, tinkering about with history. And I know that you'll barely think any of this out before you do it.'

       James shook his head. 'We're plenty smart. We've thought about it loads.'

       'Oh?' Rose replied, her eyebrows shooting up. 'Is that so? Well, then I assume you've already realized that there's no point in your attempting anything at all without first knowing what, precisely, this pan-dimensional key thing actually is?'

       James rolled his eyes dramatically and spread his hands, as if to say, well duh, of course we've already figured that much out, but the effect was ruined by Ralph's querulous response.

       'Er, no,' he said, frowning, and James slumped. 'We just thought we'd travel back to the day when Magnussen escaped and try to follow him into Muggle Philadelphia. He'd just lead us to the key, wouldn't he?'

       'Nice to know you've given this some serious thought,' Rose said wearily. 'Have you asked yourselves how you'll even recognize the key?'

James looked at Ralph for a moment, and then glanced back at the Shard. 'Well, I mean, it's a key. It'll be obvious, er, won't it?'

       Scorpius spoke up now. 'It could be anything, Potter. For instance, if your theory is accurate—and I'm not entirely sure that it is—then the 'real thieves', as you call them, have accessed this Nexus Curtain using a piece of