Hey kids! Wolf Girl here, and I'm excited to bring you this crossover fan fiction. My three favorite fandoms are Doctor Who, Sherlock, and Harry Potter, and I finally found a way to intricately weave them together. I'd like you to keep in mind that this is being written for the fun of it, so it will be light-hearted and amusing for those who enjoy these characters (oh but don't worry, I may pull a Moffat or two ;) )

Anyways, I'll write as often as possible, and any/all reviews are much appreciated.

Cheers!

Cutlery clinked as Jim Moriarty savored his dinner. He cheerfully hummed Staying Alive by the Bee Gee's as he lifted a water glass to his thin, dangerous lips. Footsteps could be heard approaching from behind; Moriarty's behavior did not deviate, but it was obvious that wheels were turning in his head. He returned the glass to the table, and said "Ooohh... I have no idea how you got in here..." He sprang out of his seat like a jack-in-the-box. He turned to face the intruder with a huge, maniacal grin. "But I love it! I absolutely love it! Can I offer you a splash of tea? A biscuit?"

The intruder was a man, standing statuesque in a doorway. He was well dressed in a tailored suit and his appearance was well groomed. Jim Moriarty practically danced over to him. "How did you do it? Why are you here? Who are you?"

The man smirked a little bit. "My, you are an excitable one, aren't you?" Moriarty pursed his lips and his eyes bulged with anticipation. The man sighed. "Some people know me as Harold Saxon, but I prefer to be called the Master."

"Mmm that's a bit grandiose..." mumbled Moriarty as he began methodically pacing around the Master. "And you are here why?"

"You have something of mine. I need it back."

Moriarty grimaced. "Oh, well, you know, finders keepers."

"Ugh, you humans..." The Master rolled his eyes. "You don't understand the severity of the situation." He cleared his throat and straightened himself out. "I am time lord from the planet Gallifrey. I went through great lengths to obtain a universe jumper. However, it backfired, and now I'm stuck here. I need it back so I can fix it and return to my universe."

Moriarty stopped pacing. His eyes bore into the Master's and he cocked his head like a puppy does when they are confused. "Say what now?"

"Listen to my chest, I have two hearts."

Moriarty gasped. "But sir, I hardly know you!"

The Master groaned and grabbed Moriarty's head, pulling his ear to his chest. Wide eyed, he listened to one side of his chest, slid over to the other side, and sure enough, there was a second heartbeat. Moriarty huffed as he pulled back. "Wow, and I thought I was a freak..." He took a few steps back, crossed his arms, and became serious. "So now that I know what that thing is, what's to stop me from killing you right here and use it for my own person gain?"

The master scoffed and explained "Well you can't kill me, I'm a time lord. I'll just simply regenerate."

"Oh, fun! Let's test that theory, shall we?" In one fluid motion, Moriarty drew a pistol and fired it directly into the Master's chest.

A very disgruntled woman in a man's suit that sagged loosely over her body sat across from Jim Moriarty. Moriarty was leaning his face on his hands, gazing at her, completely enamored. "This... is... incredible!" laughed Moriarty, clapping his hands. "You can't die, you just burst into this fancy fairy light and form a new body?"

"Essentially..." she answered. She began loading her tea with a ridiculous amount of sugar.

"And you have this nemesis that has a vessel that can travel through space and time who keeps thwarting all of your evil plans?"

"Yes."

"So you made a device that disables his machine, catapults him into a parallel universe, and traps him there... but it backfired and you got dragged along."

"Yes, this is exactly what I just told you. I'm sorry if your tiny human brain has a hard time grasping this." She took a sip of her tea. "It didn't disable the TARDIS, so he's still flying around this universe. I want his TARDIS completely disabled, and I want to go back to my universe. So, I need my device back."

Moriarty smiled wide and leaned back in his chair. "Tell you what. I'll give you access to your little machine and I won't have a sniper blow your head off if you show me how it works. Let me watch you fix it."

She shrugged her shoulders. "Ok. It's not like you'll be able to understand it anyway."

"Also," he continued darkly, "I have a little nemesis of my own who could stand to be thrown into another universe."