I chose Snape/Tom Riddle Jr. for a writing challenge. My research (aka checking the wiki) shows that Snape hadn't even been born yet when Tom Riddle Jr. decide to discard that name.

Now I could just say "okay it's an AU where they were born at different times and went to school together", but... uh... I didn't want to?

Instead I'm going to use My Immortal references and introduce time travel. Because, you know, that's so much simpler.

"The Dark Lord Voldemint, still in his school days, suffered a most terrible heartbreak. Had this not happened, perhaps there would be no Volxemort..."

Severus Snape, third-year Slytherin, stared at Sybill Trelawney. "What?"

"... I'm sorry, I spaced out for a second there. Did you say something?"

"... No, I didn't." Was that a prophecy? I've been told that prophecies tend to sound strange, but that was... really just weird. Also, they usually tell the future, not an alternate past.

"All right then," she said, and continued on her way.

Severus and Sybill weren't exactly friends. In fact, they hardly knew each other. But everyone knew that Sybill was a Seer... except Sybill herself.

He wandered off, pondering the implications of this prophecy (particularly the part where the Dark Lord's name was mispronounced two different ways), and was lost in his own thoughts when he bumped into Dumbledore, causing both of them to drop a fair number of their possessions.

"Sorry, Headmaster, I should have been paying attention..."

"No need to apologize, Severus, I, too, was not looking where I was going..."

A few hours later, Snape was digging through his possessions for a lost assignment when he found a small rectangular device he had never seen before. "Oh, I must have taken this by mistake, when... huh."

Etched on the device, quite clearly, was the copyright date of 2006, far in the future. "How strange." Snape wasn't familiar with the details of copyright law, since it was irrelevant to his ambitions, but he was pretty sure that writing a copyright date two decades in the future was a bad move.

He pushed the most obvious button on the front of the device and was only slightly surprised to see it start to change shape and expand.

He was rather more surprised when it continued expanding beyond the size of his head, and completely baffled when the transformation finished to reveal a Muggle car.

"What?" he said, for the second time that day.

"Nice Delorean, Snivellus, who'd you steal it from?"

"Shut up, Potter." Guess I'm not hallucinating.

"Make me."

"Silencio." Snape stared at the car for a few more seconds, still completely lost as to why Dumbledore would be carrying it around. This train of thought was cut short by a curse whizzing past his ear. He spun around to see Sirius Black, pointing his wand at him and looking very grumpy indeed.

"What'd you go and do that to James for, huh?"

"I do not have time for this." Snape got in the car, turned the key, and drove off.

Sirius cast the anti-Silencing spell. "That was weird. Did you see it too?"

"Yeah. What the fuck's Snivellus doing with a Delorean?"

Unfortunately for the two of them, Back to the Future would not be released for two more years, so they were unable to make any clever time-travel jokes.

He had less than a minute of driving experience and already Snape could see why Muggles liked it so much. He pushed the gas pedal down as far as it would go, curious as to just how fast Muggles could make a thing go.

Yes, he hit eighty-eight miles per hour. Yes, he broke through the space-time continuum.

He immediately slammed down on the brake pedal. "What the everloving fuck?"

Once the car came to a complete stop, he turned it off and pulled on the key. Strangely, this caused the car to revert to its original shape. "Oh, great, now that thing's even more anachronistic."

"Excuse me."

Snape turned around to see a familiar face. It was Tom Riddle, thirteen years old and not yet Voldemort. Snape recalled Sybill's words. "Oh, no, that is utterly ridiculous and I refuse to do it."

"You refuse-?"

"Oh, I apologize, I wasn't talking to you just then. Um. Have I interrupted something?"

Tom stared incredulously at Severus.

Severus looked around to see several students in dark robes and masks. Clearly, this was a meeting of... not the Death Eaters, those didn't exist yet, but... some sort of proto-Death Eater group? "Ah. Well, I'll just be getting out of your way..."

"I think not. Imperio."

You. You will stay here until the meeting has ended, and then we will speak.

As Snape regained his senses, he quietly thanked any powers that might be that the future Dark Lord had only forced him to stay there until the end of the meeting. At thirteen years old his Imperius Curse was likely not very powerful - but it was still the Imperius Curse.

"So. What is this?" Tom asked, holding up Dumbledore's device.

"I'm not entirely sure, actually. It can turn into a Muggle car, for some reason."

"Lies. I pushed every button on this device and it has done nothing."

"What? Why? It worked for me." Snape snatched the device out of Tom's hands and started pushing the button that had changed it before. "... It's not working."

"I can see your thoughts. It has never done anything, has it?"

Snape frowned. His thoughts were quite clear on the matter. Perhaps Tom hadn't yet learned Legilimency and was merely bluffing. "No, it works exactly as I said. Or it did."

Tom stared into Snape's eyes.

"Look, I took it from Head- I mean, from Professor Dumbledore, so maybe he knows how it works."

You will not speak to him.

Snape winced. If this was how the Imperius Curse worked, he could see why it was Unforgivable.

"It does not matter. The device is not what I wished to speak of."

Snape held his face expressionless.

"To be frank..."

YOU WILL SPEAK OF THIS TO NO ONE.

"... I find myself desiring you."

"What."

"I place myself in a very vulnerable position by revealing this to you," he continued, ignoring Snape's words, "yet the feeling itself is vulnerability enough that it is very little of a danger in comparison."

"I- I can't. I have to go." Snape stood up to leave.

YOU WILL NOT LEAVE.

"I... have to get back..." He wrenched his thoughts away from the future Dark Lord's control and went towards the castle.

"He... resisted me. Completely."

The future Dark Lord was feeling something very unfamiliar right now.

"Professor Dumbledore!"

"Yes... I do not believe we have met, young man."

"Um, yes, about that. I seem to have gotten myself into some trouble. With Time."

"Oh dear."

Shortly thereafter, Snape had been returned to his own time, though without the memories of his little jaunt through causality.

The Dark Lord had resolved never to feel love again, as his very first experience had ended poorly.

And, well, you know the rest of that tale.