Thank you everyone for your lovely comments and faves. I believe we're half way though the story now. Happy 12/21/12 everyone.

Stiles' room reeked of sex. Derek held his nose as he stood in the teenager's room. Derek wished it smelled bad instead of potent because Derek didn't want to confuse his senses of Stiles. He needed to keep things strictly impersonal and he didn't need this scent in his nasal inventory. Stiles was not allowed to smell this good. Derek breathed out sharply, trying to ignore it. It was obvious that Stiles had not been lying because of his steady heartbeat, but finding evidence of his own scent mixed with Stiles' just made it more real. It just made Derek all the more determined to rip the imposter into pieces.

Derek prowled around, regaining his bearings after he grew used to the scent. The Sheriff wasn't home, most likely out at work. Stiles' computer was on and humming, but asleep. Derek wasn't going to touch anything. He wasn't there to scare the crap out of Stiles this time. He was there to try to find a lead to where ever this cambion was. It smelled like him, but Derek always found his own scent hard to track. Staking out for the cambion here while Peter was explaining things to the boys was easier.

It was dull waiting. Derek sat in the dark, senses open for any sign of odd movement or approaching sound. If he heard Stiles he would bolt, wanting to make sure he didn't confuse Stiles any more with those adolescent hormones. Stiles wasn't in love with him, Derek thought firmly. He was sure this cambion just lied really well and manipulated Stiles into feeling exactly what it wanted Stiles to feel. Derek always pushed Stiles away when he could, so there was no reason for the teenager to feel anything for him. Before today, he thought that he was secure from anyone's rampant emotional attachments.

The sound of someone on the roof made Derek lift his head slightly from sitting in Stiles' computer chair in the corner of the room. He watched with the glow of streetlight, seeing a body that looked strikingly familiar sliding easily into the room. Derek's eyes narrowed, seeing his own solid build in a t-shirt and tight jeans. Derek's claws grew out from his fingers and his muscles tensed. He was barely 10 feet from his mirror image and the other seemed completely unaware. If the fake moved closer, Derek could leap and still have the element of surprise.

His mirror image stopped though, his head tilting, as though sensing something and his hands were on the window sill, poised to close.

"Funny." The low tone of his own voice made Derek perk when red eyes reflected in the window light to look at him, "I didn't think you'd be back so early." Derek bore his teeth and a smirk glinted on his reflection's face. Derek lunged forward and the fake jumped back out the window, surprisingly swift. Derek flew out after him, seeing his double run down the street towards the woods. Derek gave chase.

Peter hadn't been kidding when he said a cambion took the person's body because as fast as Derek was, so was the imposter. He could even run on all fours once they made it to the woods. Derek disliked the length of the chase and the other kept looking back at him, as though making sure Derek was still following. It felt too much like a trap. But Derek was not willing to let this thief to get away, not when Derek had a perfectly fine supply of hot rage to inflict upon his double. The fact that he looked like him did not faze Derek's blood lust.

Finally, the imposter rolled down a hill into a thicket of bushes and when Derek leaped over, his double was there to meet him, slamming him into the weeds and the scent Derek like a truck. Wolfsbane, fresh overgrowths of it. Derek snorted to clear his senses and the double was on him in a flash. Growling and snarling was only the beginning of the myriad of sounds that erupted from the grove as they tore into one another. Blood flew from both Dereks and when they both broke apart they were panting, torn to the bone and both transformed, circling each other. Both were also weakened by the wolfsbane.

"Feeling sleepy yet?" the fake jeered with a smirk, one eye closed because there was so much blood flowing into it. Derek rolled his neck and a few resounding cracks filled the stirred air and he popped his jaw back into place with his knuckles and spat out blood onto the purple peddles.

"Don't sound so cocky." Derek warned, "If you have my body, you're weakened too." the fake's smirk didn't falter. Both of their wounds were slowed to heal, the wolfsbane pollen covered both of them. Derek coughed, hating to admit that this was rather clever for some sex demon. The cambion nodded his head slightly to the side with a small shrug, as though agreeing on the theory. He looked surprisingly calm for one that had blood running down his neck.

"Well yes, I feel rather nauseous, actually." the fake admitted, "And light headed, as though as this burning sensation in my throat. Can you taste it?" the cambion ran his finger pads down his throat, right where Derek felt the burn as well, "Well worth it to get you down to a manageable level." Derek growled, eyes flaring. He decided to finish this fast and get out before he breathed anymore of the dizzying smell. Fighting in this patch was not to his advantage. The cambion was more bloody than he was, closer to death, Derek was sure.

The cambion dodged his lunge and Derek felt claws in his back as another close combat struggle ensued, bringing both closer to their limits.

Then the cambion broke off, starting to keep his distance from the real Derek, who snarled. Derek's vision was blurring and the cambion was also stumbling, only keeping upright by finding a tree and digging its claws into it. Derek coughed up blood, slightly blackened because his body was not coping well and he fell to his knees.

The cambion gasped and coughed out a laugh. Derek looked up, wondering how the hell a dying creature could sound so cheerful, "Oh, oh god, the look on your face. You think you've made some progress?" the fake slid down the tree, "foolish puppy, do you even know what you're dealing with?" the cambion's skin rippled and grew smaller as Derek blinked, trying to continue seeing, but his eyes just wouldn't focus, "Unlike you, I have another body to change into." Derek heard leaves rustle to his left and Derek's claws reached out, but the hand was stomped upon.

The voice was higher pitched than his own. It sounded familiar, "Easy sourwolf. We're going to have some fun..." Derek's body disobeyed him, muscles refusing to move for him, vision going dark.