Author's Note: So, I should be working on my other story, but this idea came to me today and if I postponed writing it, it may never get done. That said, this is an AU story about how Grindlewald and Dumbledore met. Grindlewald wasn't expelled from Durmstrang and he is older than Dumbledore.

The idea came to me while I was sorting socks from my clean laundry. It probably has a ton of mistakes because it hasn't been beta-ed or reread by myself. I'll probably clean this up later, but as I said... I'm really bad about doing things quickly so I wanted to post this before life got in the way. I hope you enjoy!

Last thing... there isn't a chronological list of Hogwart's headmasters, but I think there is a very good chance of Phineas Black being Dumbledore's headmaster. The timing does fit. If anyone has better suggestions, please let me know.

Disclaimer: I don't own Harry Potter.

The Sock Thief

At first, nobody thought twice about it. It was a well known fact that socks were more magical than most clothes (even though Muggleborns always assumed it was the pointed hats or something equally ridiculous), and it was viewed as something as a cosmic joke that socks happened to have an independent streak even though they were always produced in pairs. So if after casting cleaning and refreshing charms, one sock mysteriously disappeared, well, nobody thought much of it.

But in the winter of 1898, an epidemic occurred at Hogwarts School of Witchcraft and Wizardry. Socks - not just one or two, but every other pair seemed to be leaving at an alarming rate. At first, students just chalked it up to magic. They would reappear eventually. When they didn't, it became clear that something unusual was occurring. Students employed a variety of measures to entice their socks to return or stay: some started cleaning their feet more thoroughly, in case the bad smell was scaring them off; some started casting sticking charms on their socks before going to bed at night. The students from well off families even had their house-elves leave their traditional family home to come guard their socks in the dorms. With only two weeks until Christmas left, the teachers also started experiencing problems. Something had to be done.

Headmaster Phineas Black decided that drastic measures were needed. He floo-called up the Auror Office, but they wouldn't take the case. It was just his over-imagination, they laughingly told him.

That was how the case ended up before Gellert Grindlewald's desk.

Grindlewald had graduated two years earlier from Durmstrang, with lots of ideas and little money. So before he could introduce sweeping reforms into the German Ministry of Magic - reforms that would challenge the Statue of Secrecy and revitalize the stagnant Wizarding world while bestowing some magical medical options to ignorant Muggles - he needed a job. The German Ministry didn't have any vacancies - but England and France both did. Being a proper German, he flat out refused the French and moved to London to work with the Detective Division of the Aurors Office. His brilliant mind had easily solved all the cases before his desk, and when Gellert entered work that morning and saw the floating box flashing the words NEW CASE, NEW CASE, he did not think much of it.

Opening the box, he found a briefing about the case and several... socks? Glancing at the title of the paper gave him further pause. The Sock Thief. The Department must be seriously bored if they were giving him cases like this. What happened to mysterious stabbings and corruption?

Yet despite its unusual content, the case seemed fairly straightforward. Too many socks had gone missing from Hogwarts too be chalked up to the usual shenanigans of socks; the headmaster thought it was most likely a student playing a prank. However, the Hogwarts staff had been putting up a variety of high level transfiguration, charms, runic, and mild curse spells, yet the culprit (who shouldn't have recognized, let alone successfully gotten past these) continued to steal the socks. The Headmaster was stumped and had respectfully asked the help of the Aurors. The following socks were the counterparts of socks that were particularly sentimental to the owners - Christmas socks, hand-woven socks, even one sock that was labeled one of the two 'lucky socks' of the distraught student.

Gellert snorted in disgust. Here he was, sorting through socks. He deserved a raise.

And honestly, the British Wizards must have pudding for brains. The answer was obvious, staring up at him from the page. This was the work of no student!

Fact: The culprit had gotten around highly complex magical barriers with ease.

Fact: As all of the victims were at Hogwarts, the culprit most likely lived at Hogwarts as well.

Fact: The culprit had a decided fascination with socks.

Fact (the most unusual of them all): The students who had employed personal house elves to guard their socks had not experienced further theft.

This could only leave one possibility: a rogue house elf. House elves were not affected by Wizarding magic in the same way Wizards were; furthermore, house elves had their own very powerful magic. Lastly, while rare, there were rogue house elves. These elves usually had a preoccupation with clothes, since clothes had such symbolic significance to that race.

Gellert put on his coat and hat as he headed towards the door. All he had to do was catch the house elf and this case was finished. Then maybe he'd get a real case to work on.

Grindlewald quickly gained permission from the headmaster to set up traps. He also gained information on where the house elves usually congregated, much to the bemusement of the Headmaster Black.

Gellert visited the kitchens and the four student common rooms and laid out the bait: a single white sock at each location. He had bought several pairs before heading over to Hogwarts and along the way had added spells designed for trapping magical creatures as well as some more obscure Wizarding spells that the house elf may not be immune to. He left the socks in the corner of each room, out of the way but hopefully visible to the sock thief. The thief would be wary, no doubt, but also overconfident from previous success. Gellert cast one last monitoring spell over the socks, so he would be notified when they were tripped. Then he left for the day.

The first alarm went off that evening. After apparating to Hogsmead and walking quickly up to the castle - would it really be a bother to add apparition points! - he followed the spell to one of the common rooms. So it was, as he suspected, a house elf with dorm duty and not one of the kitchen helpers. Predictable. But when he stepped through the portrait's door, he was greeted with an unexpected sight: a student was bound up. Upon seeing him, the poor girl started babbling "I'm so sorry, I just saw the sock and it looked so much like my missing one, I should have known other people own white socks and that this might have been a trap but I'm not the thief, I'm so sorry, please release me." Gellert had unbound the spells while the girl talked, then stalked out of the room without bothering to respond. He got three other calls - at various times throughout the night - for the other dorms. In each case, a student had spotted the sock and thought it was one of their own. Or in the case of the student from that dungeon common room, he had picked the sock up regardless of whether or not it was his. The annoying blond had continued whining about how many of his socks had been stolen and if someone was stupid enough to forget their sock, then they didn't deserve it anyway.

By the time morning arrived, Gellert had a headache from thwarted plans and a night's interrupted sleep. Curiously enough, the sock in the kitchen hadn't been touched. All of the house elves there had given it a wide berth, afraid of coming too close and being freed. Instead of weakening Gellert's theory, he only became more convinced that the culprit was a house elf. Obviously, it had seen the sock placed there and - knowing no elf would leave it there - had figured out that it was a trap for house elves and avoided it. A most cunning elf.

But Gellert Grindlewald was never defeated, especially by a house elf! He had another plan. This one required some sacrifice on his part, but it was all for the greater good. That night, he posed as the new assistant professor for DADA, who had just finished up some research in South America and could only now arrive at Hogwarts to help teach. There wasn't much applause following the announcement, but Gellert thought his cover was believed. He took up residence in the teacher's wing that night and carefully laid out all of his socks in the drawer. On top he placed his most treasured socks - hand knitted woolen socks, made for him two years ago by his mother before she died. He hadn't originally wanted to include these - but after the failed attempts with the plain white socks, Gellert wondered if perhaps the thief was becoming picky. So he loaded even more curses and traps onto the thick fabric. He wouldn't - couldn't - be thwarted this time.

The first night passed uneventfully, but maybe the elf was still cautious since seeing the sock in the kitchen the night before. His unexpected arrival might seem very suspect.

The day passed uneventfully: or, as uneventfully as possible while trying to pose as an assistant professor in a room full of ignorant and unruly students. There was one class that wasn't so tedious. The seventh year class, which met in the afternoon, had been unexpectedly pleasant for Gellert. There was a student who seemed almost as intelligent as himself. He had mastered the new teaching material in minutes and quickly moved onto modifying and improving the spells. This student's name was Albus Dumbledore.

After making some small conversation after class, Gellert was impressed - and intrigued by the precocious student. Never before had he such a pleasant talk with another, without feeling the need to slow down his thinking or explain his thoughts in simplified terms. It was an addicting feeling.

The next two nights passed similarly uneventful and the days were filled with 'accidentally' passing Dumbledore through the halls. After a particularly long discussion in the library, he started calling Dumbledore 'Albus'. Gellert was beginning to despair about the case ending - for then he wouldn't have a chance to speak with Albus - and of the case not ending - which would mar his impeccable detective record.

On the third night, Gellert had given up on expecting the thief. He would have to devise another plan tomorrow. He fell asleep that night with expectations only of meeting Albus the following day and finishing their discussion on alternative uses of dragon's blood.

They met sooner than expected. The alarms went off in the early morning, jolting Gellert awake. The thief had struck! The question was, whether he was caught or managed to escape with Gellert's beloved socks. Waving his hand, a lumos burst forth over the room and there, standing beside his dresser and holding his mother's hand-knit socks was none other than Albus Dumbledore.

Albus Dumbledore. Not a house elf. Gellert almost wanted to ask what Albus was doing there, he was so convinced that the culprit was a house elf. But why else would his friend be stuck in the socks' multiple protective spells? And then in a flash of insight he understood how incorrect his previous assumptions were: Albus was smart enough to outwit the teachers, and Albus was bored and brilliant enough to devise a scheme to steal socks from the school's inhabitants. And Gellert had caught the sock thief, hadn't he? So why did he feel cheated; angry that his theory had been outwitted and outmatched by another?

Meanwhile, Albus had been examining and dismantling the spells on the socks. "Very unusual protections, you've got on these." he remarked, blue eyes twinkling. "Were you expecting Nifflers to come steal your socks" he asked as he dismantled one of the magical creature trapping spells.

"House elves, actually." Gellert responded stiffly, mind still churning over these unexpected events.

Albus' grin widened into a full fledged smile at this. "Not many remember the abilities of house elves." he commended. "I had completely forgotten about them, myself. Almost got caught when some of the Slytherins got house elves from home to start protecting their socks." Albus had finished undoing the spells and could now move again. "So what now?" he asked, as they stared at one another.

What now indeed. Gellert understood the motivation that drove Albus to do this - indeed, he had contemplated many far fetched schemes while he was still stuck in school, and boredom was a powerful motivator for a brilliant mind. On the other hand, the situation had gotten to where the Aurors had been called in - who knows what the repercussions might be for Albus?

Sometimes, Gellert reflected, the greater good wasn't always the most appropriate response.

"Return all the socks to me." he stated in a bored drawl, trying to convey how childish he thought this whole thing was. "I'll buy you a pair of socks for Christmas, since you seem to want them so badly."

Albus' cheeks were reddening in embarrassment - in a most becoming way, Gellert thought absently - but he recovered quickly and responded with a large smile and a response of "Two pairs. I'll be at Godric's Hollow for Christmas - stop by anytime." before leaving through the door.

The next day, a large box appeared outside Gellert's door containing all the missing socks. Gellert filled out the paperwork for the case and surprised the entire staff when he identified a house elf as the culprit (he needed one anyway, and had already approached said house elf about working for him after it was fired from Hogwarts). After returning the socks to their rightful owners, Gellert left Hogwarts with the satisfaction of a case well done. Even if his theories hadn't been correct, at least everyone else thought they were. And now he had an address - and an invitation - to contact the first person he had ever found equally intelligent and engaging as himself. And said person was graduating soon. Gellert looked forward to increasing his burgeoning friendship - and perhaps something more - with the sock thief Albus Dumbledore.

Perhaps Britain wasn't such a bad place to work after all.

A/N: This is my first oneshot, but I thought about making it longer... Does anyone have any ideas for another mystery for Detective Grindlewald?

And, please, please review! This story was rather rushed, so constructive criticism is very much appreciated!