"So if we could just bind the charm to the phone with a set of runes, it should function like a small magic-impervious bubble and shield the object," Draco said, running through his calculations again. "The problem is that magic can't be cast within the active space of the charm, so I have to figure out how to get the area just large enough to cover the device, but not the surrounding space."

"I'm sure the Aurors will want that charm, though," Astoria mused, poring over her own notes. "So far they're only able to put magic-suppressant charms on handcuffs and cells, and they'd pay to be able to make their cells spaces where magic can't be cast at all. Make sure you sell for a high price."

"Of course," Draco agreed, knowing he'd have to discuss with his instructor how best to go about it. His Master thesis was on this spell, after all, so his paper on the creation of the spell was going to be published as a matter of course, and then the spell would be common knowledge. This spell could be classed as a restricted one, though, since it could incapacitate a wizard if cast on a big enough space, and then there was perhaps the option of only Charms Masters being allowed to cast it – in which case Draco could make the Ministry pay him to cast the spell on their cells.

But first he and Astoria needed to figure out how to ground the spell. It wasn't like the Fidelius Charm, which was practically impenetrable, but rather a regular charm that could be dispelled with a simple Finite. That was a good thing for his Mastery, as he certainly didn't want the spell classed as a dangerous one, but created difficulties when you wanted to take advantage of the spell for electronics.

"This is brilliant, though," Astoria told him, not for the first time, and Draco felt the glow of pride. "The spell can be cast easily anywhere, anytime, and dispelled just as easily! The Ministry can't complain about it being dangerous, either, because someone inside the spell can still use a Finite on it – how does that work, anyway? – but once we figure out how to anchor it and make it permanent the Ministry will be more than happy to take advantage of it for their cells." She looked up, pride in her eyes for her fiancé's accomplishment. "Brilliant, Draco."

Waving off the praise though he knew he wasn't fooling his fiancée one bit, Draco turned back to figuring out how to change the size of the spell's active space. If they could figure this out, they could make a killing off modified Muggle electronics – the Quidditch market alone would make them rich, what with the items needed to record matches live and broadcast them to the television sets they would also have to modify to work in a magical household. Phones, computers, music players… From his job at the electronics store Draco had learned how to the small shop got permission to sell branded electronics, and they could simply do the same thing – sell on electronics just like one of those stores, except modified to work for witches and wizards.

Casting a passionate look at his fiancée that she didn't see, Draco lowered his head to his calculations. They first had to figure out how to do it.