"Sherlock! Wait up!" John yelled, chasing the sixteen year old across the grounds of Hogwarts.

"C'mon, John! There's something I want to show you!"

John Watson swore under his breath and stopped in his tracks. There was no way he could catch up to the younger boy; he was too short, and Sherlock had shot straight up over the summer. John crossed his arms and stared at the patch of trees at the end of the Forbidden Forest that his friend has disappeared through, waiting.

Sherlock came back out of the forest and yelled, "What are you doing?"

"You never wait for me, Sherlock. I always went at a pace you could keep up with when you were shorter than me!" John started toward the forest again.

"Or you could grow a few feet, you freakin' Hobbit."

John shoved his friend when he got close enough. "Shut up, bean-pole."

They laughed and Sherlock led them, slower this time, into a clearing in the forest. "We're not supposed to be in here, so this better be good."

Sherlock smiled slyly. "Look what I discovered over the summer." He snapped his fingers and suddenly, John's best friend was shrinking and changing, until a large, black panther was circling him.

John's smile faded to a look of pure shock. The panther's eyes were unmistakably Sherlock's the steel around the elongated pupil seemed to laugh at his surprise. The muscles in his shoulders rippled as he paced the clearing, the glossy coat gleamed like a river of black in the patches of sunlight. John couldn't move. In the blink of an eye, Sherlock stood in front of his friend again, smoothing out the wrinkles in his uniform and smiling like an idiot.

"How did you..." John still couldn't think.

"I was born with it. I'm an animagus. Turns out, some animagi can't transform until later in their life, and some can from birth. Mum and I were having dinner when we found out I had this ability. I sneezed sort of violently, and suddenly there was a large jungle cat in my mother's kitchen. She fell off her chair in surprise."

John burst out laughing picturing the sight of his best friend sneezing himself into an animal. "That's so cool, Sherlock! So now whenever that one Slytherin starts messing with you, what was his name?"

Sherlock frowned. "Anderson."

"Yeah. Well, now you can just scare him into leaving us alone!"

"Not so. Turns out, there's a whole list of rules you have to follow as an animagus. 1. You have to be registered, which I did. 2. You can't use it for evil, pranks, anything like that, or you could have some serious consequences. Among others."

"Since when do you listen to rules?"

"Since my mum threatened me with a trip to the vet if I didn't behave. I don't know what that is, but I don't want to find out."

John's muggle knowledge came in handy once, and he burst into another round of laughter. Sherlock smiled and threw an arm around John and led him out of the forest. "I can trust you to keep my secret. Last thing I need around here is another reason for them to treat me like a circus side-show."

John nodded. "Of course. You kept the secret about what happened to me last year with that incident with the girl's lavatory."

"You forget, John, that that's my secret as well. We got into quite a mess with that situation." He laughed.

"Yeah. Poor Myrtle, though."

Sherlock shrugged. "The whole thing was basically her fault, I feel no guilt in what happened to her in the end."

John rolled his eyes. "Of course." He suddenly took off sprinting across the grounds again. "Race you to the Great Hall!"