It was clearly their kind of case. Three bodies had been found in the space of two days around a small town in South Dakota. It would have seemed like nothing unusual except that all three victim's hearts were missing.

"I'm almost certain it's a werewolf Sammy." Dean said to his brother who was sat beside him.

Sam shrugged "Werewolf seems like the obvious answer but there are plenty of other monsters that take hearts Dean." he retorted

"Or it could be a human." the angel Castiel chimed in from the back seat.

Dean gave a shudder. He didn't know what he'd do if it was a human. Monsters he could deal with but people were crazy.

"It's not a human." he said firmly,not letting himself even consider for a second that the thing doing this was a person just like him or his brother, except more sick in the head.

Sam and Castiel sensed the warning tone in Dean's voice and stopped talking,allowing the eldest Winchester to drive in peace.

"Why are we here John?" Sherlock demanded as he sat beside his partner in the yellow taxi that was currently driving them through South Dakota.

John gave a little scowl in the detective's direction "We were supposed to be on holiday but you were driving me nuts going on and on about being bored so now we're going to solve a bloody case instead of having a relaxing break."

Sherlock exhaled "It's still not the most fascinating case. Just some American cutting out people's hearts, nothing very interesting but it's better than having to go along with you on your sightseeing."

John felt a little bit hurt "I thought you liked going sightseeing with me yesterday."

Sherlock shook his head, dark curls bouncing slightly "I only did that for your sake. I despise crowds, especially those of the idiotic American variety. They don't even know what the word Floccinaucinihilipilification means."

John sighed "Sherlock I think you're the only one who knows what that means." he replied tiredly.

Being friends with a 'high functioning sociopath' was incredibly draining, even more so in a foreign country when said sociopath found even more things to rant and complain about than usual.

Sherlock lent back in his seat with a frown "For your information Floccinaucinihilipilification is the estimation of something as valueless." he muttered then proceeded to sulk for the rest of the ride.

A/N Short one I know, sorry but this is just the start, it will get more exciting I promise!

Hope you enjoyed, this is my first crossover fic so I hope you like it and please don't judge me too harshly for the portrayal of John or Sherlock, I haven't watched the whole show yet :)