Because some people wanted this ;)

Looking up as a colleague leaned in the doorway, Jackson Punnet put on an enquiring expression.

"It's doing it again," the other man, Stanton Fields, announced gloomily.

"What's doing what again?" Jackson asked, slightly puzzled.

"The magic monitoring thingy. It's gone all strange again."

"You mean the Accidental Magic Detection And Homing Lister?" he clarified.

"Yes. That AMDAHL widget. It's gone tits up again," Stanton sighed heavily as Jackson got up and headed towards him. "Bloody thing needs a good kicking, I reckon. It's been playing silly buggers for years now, and no one has any idea why."

Walking past his colleague into the other room, buried in the bowels of the Ministry of Magic, Jackson examined the device in question, which was a complicated arrangement of crystals, pieces of carefully shaped wood, springs, a little thing that went 'poot' every seven point two seconds (which no one had the faintest idea about, but if you stopped it 'poot'-ing the entire thing broke and took three days to fix,) and for some reason that had never been established, a potted fern. "Did you water the fern?" he asked, leaning in to check and sticking his finger into the soil.

"Of course I watered the bloody fern! Do I look like an idiot? First thing I checked, that poxy fern. It's fine." Stanton glared at him. "It's never the fern."

Sighing a little at his companion, who was hard work a lot of the time, Jackson fiddled with the device rather gingerly. After several minutes and one tooth-rattling jolt from the main magical power bus, he turned to the other man. "Looks fine to me."

"Says the man who has no more idea about how that thing works than anyone else does," Stanton replied with heavy sarcasm. Which was true enough, the thing was over four hundred years old and no one had the vaguest idea where the plans, if any had ever even existed, had got to. Neither did anyone really understand how it did what it did, only that it it did in fact do it. Most of the time. Except on the second Tuesday in March on a leap year that contained the number two, when it instead tended to write very bad poetry.

That was magical devices for you. They were a little weird at the best of times even to wizards.

Turning to the output scroll, he picked up the parchment that was sitting in the bin and looked through it. The background magical level wobbled up and down like a wobbly thing, averaging a more or less constant level with the occasional spike. When certain classes of spike happened, they were annotated with various figures that indicated roughly what they were and where, along with a time. The device was also supposed to make a sound, but sometimes it didn't and saved them all up for a while, then frightened the life out of them by making a terrible racket for a few minutes. Jackson was fairly sure it did that just to liven things up, but he was never going to admit that to anyone else.

Unrolling the readout he scanned the results before sighing. There was an intermittent low level, in fact incredibly low level, almost nonexistent, signal that came and went apparently randomly. It was recognizable as they'd seen it happen intermittently for at least the past year, but no one had the vaguest idea what caused it. Certainly not accidental magic as that was very distinctive and instantly apparent, although that only applied past a certain fairly high threshold, below which it was filtered out since otherwise the blasted machine would be constantly registering hits. There was such a thing as too sensitive. And any accidental magic below the set threshold was too minor to bother about anyway, since the Muggles would only put it down to chance, or low flying clouds, or too much alcohol. Some prosaic and mundane explanation, certainly.

They weren't very observant, Muggles. Which made their own job easier but was yet another reason to avoid the creatures.

The system was more usefully used to monitor underage wand use, which was the main purpose of it these days, despite the name. Any wand with the Trace alert linked to it would immediately generate a precise location and time, which could be cross-referenced to a known magical household and used to determine whether a warning was issued, and in more serious cases, the cleanup squad sent out to fix things and wipe the memories of any Muggle witnesses. Obviously, Pureblood households were excluded from that as they always dealt with their children's excesses themselves as was their right. They also had the sense not to perform magic near Muggles.

"I wonder what that is? Equipment error, or something real?" he mused out loud, winding the scroll up again and putting it back into the output bin. Whatever it was, if it even really existed, didn't look even remotely like actual magic, and couldn't be localized. It was just there. Or not, depending on whether it was a real reading or an instrumentation error.

"Probably the bloody contraption is wearing out, finally," his colleague replied sourly, giving the device a harsh glare. "It's already apparently allergic to the Oxford area. We haven't had a hit from anywhere within twenty miles of the place for nearly a decade and no one knows why."

Jackson nodded thoughtfully. That was true enough. There had been a marked falloff in results in several areas around the country for reasons no one could work out even after a fair amount of checking. The prevailing theory was that there simply weren't that many Muggleborn in those zones due to the vagaries of fate, and it left holes in the map.

"Possibly," he allowed, looking back at the horrendously complex device. It pooted at him. "Probably just noise. If it's wearing out, it might be getting prone to false readings."

"Damned annoying, it is," the other man grumbled. "It's making a mess of the archives. I get blamed for that when someone gets all huffy about the parchmentwork, and it's a pain in the arse. Nearly got a pay cut last month over this bloody pile of rubbish."

Thinking for a moment or two, Jackson finally snapped his fingers, then dug around in the drawers on the other side of the room. He eventually emerged with a dusty book, holding it triumphantly aloft.

Stanton looked at it, then him. "What's that?" he asked.

"The closest thing we have to a manual on that thing," he replied, jerking his thumb at the AMDAHL, then paging through the handwritten book, which was more accurately a collection of notes made by a whole series of operators over many, many years. There were sketches of various parts of the thing, some annotated with cramped writing and the occasional warning such as "DO NOT MOVE THIS LEVER PAST TEN DEGREES! IT TOOK FIVE WEEKS TO GET RID OF THE CARNIVOROUS WOMBATS AND HUXLEY IS STILL TERRIFIED OF BEES."

Jackson looked at that sentence, at the machine, shuddered a little, and quickly turned the page. He found what he was looking for a couple of minutes later. "Aha! I knew I'd seen this bit before," he exulted as he moved back to the device and knelt next to it. Pulling out his wand, he studied the notes carefully for a moment, then nodded to himself.

"What are you doing?!" Stanton hissed, looking with alarm at him, then towards the door to the corridor. "We're not supposed to play with it!"

"I'm just turning down the background sensitivity a smidge," Jackson replied, concentrating on what he was doing. Prodding a couple of parts of the device with his wand, he muttered the right words, before smiling a little. "If it's picking up things that aren't there, this should filter them out. Same thing it does to minor accidental magic, so stop griping."

"We don't fiddle with the bloody thing!" Stanton growled. "What happens if you break it? We'll never hear the end of it."

"Relax, I won't break it. I know what I'm doing."

The loud pop that ended up with him upside down on the other side of the room, his hair on end, rather put the lie to that. Stanton covered his eyes and moaned. "Oh, for…" he sighed loudly.

Climbing to his feet with a wince, Jackson said, "Whoops. Poked the wrong bit there."

"Really? I'd never have guessed," the other man snapped sarcastically. "When did you first work that out?"

Making a rude gesture Jackson went back over to the device, which was pooting happily and apparently undamaged. He bent down and retrieved his wand, stuck it in his pocket, then checked the output scroll again. "See? I was right, it's stopped registering that odd signal now," he exclaimed in satisfaction. "All it needed was a little tweak."

His colleague approached and inspected the parchment as well. "It comes and goes," he said doubtfully. "Perhaps it's just not doing it right now."

"Or it is and this fixed everything," Jackson retorted. "No need to thank me."

"I wasn't going to," Stanton muttered. He took the scroll out of Jackson's hands and studied it carefully for a few seconds before shrugging. "Fine, if that works, great, and if it broke something I'm blaming you."

Jackson grinned at him. "I'd expect nothing less, old chap," he replied, slapping the other man on the back. "I'm off for lunch."

Feeling the satisfaction of a job well done, he headed out to find something to eat, leaving his colleague to grumble in his office. Which was hardly unusual.