"Now that really is creepy."

Sam looked past Dean to get a good view of the house up on the hill. He grimaced. Dean was right, the place looked like something out of a bad horror movie, all gothic architecture, tall trees and dark shadows. It was positioned on the edge of town, a steep driveway leading up to the house itself and giving it a perfect view over the entire city. They'd followed Munro, discreetly, from his office and he'd gone straight inside without seeing them.

"Could this guy be any more of a cliché? All that's missing is the bats and the scary butler."

"Yeah." said Sam, distractedly. There was still something bothering him, something at the back of his mind, but he couldn't quite work out what it was.

"Earth to Sam – hello?"

He jumped as Dean waved his hand in front of his face and turned round.

""What?"

Dean rolled his eyes.

"Oh, nothing – I enjoy talking to myself."

Sam looked embarrassed.

"Sorry, I was miles away. What did you say?"

Dean gave him a strange look and appeared to be about to say something then changed his mind.

"I said I hope this guy has an interesting social life or we're gonna be sat out here all night. I really don't feel like trying to break in tomorrow in broad daylight."

"Yeah, that might be a little conspicuous." said Sam, pushing aside the strange sense of unease he still couldn't shake.

Two hours later Munro was still inside and Dean was snoring quietly, leaning up against the window. Sam shifted for the tenth time in as many minutes and rubbed a cramped muscle in his leg. He was beginning to think the doctor was in for the night.

Just then the lights in the downstairs windows went out. He sat up, watching to see if Munro was going out or just having an early night. For a moment nothing happened, then the front door opened and Sam saw Munro step out. He closed the door behind him, got into his car and came down the driveway. Sam slid down in his seat as the car pulled out and turned left, disappearing into the distance. He reached out and shook Dean's shoulder.

"Dean – wake up!"

Dean jumped awake, blinking as he looked round.

"What? What is it?"

"He's gone?"

"Who?"

Sam looked exasperated.

"Munro. Crazy doctor, staking out the creepy house – ringing any bells?"

Dean looked blank then remembered where they were and what they were doing.

"Oh, right. Well what are you waiting for?" he said, opening the door and stepping out.

"No idea." muttered Sam under his breath, following him out of the car.

They grabbed a few essentials from the trunk, since it paid to be prepared, and after a quick look round they made their way hurriedly up the driveway. Sam was the one to pick the lock this time, Dean keeping watch behind him. Once the door was open they slipped inside, turning on their flashlights.

"You take upstairs, I'll check down here." Dean whispered, disappearing before Sam could object.

Sam hesitated, getting a bad feeling about them splitting up, but since Dean was already gone he didn't have much choice. He made his way upstairs stealthily. On the landing there was a door straight ahead of him and he went in there first. The room was meticulously neat and tidy, obviously used as a spare room since it had two single beds. He checked every drawer, cupboard and shelf but there was nothing. The next room was the same as was the third, which was Munro's bedroom. Sam was getting frustrated and as he stepped into the final room he was actually starting to wonder if they'd got it all wrong.

Downstairs Dean's luck hadn't been any better.

"Come on – you can't leave one frikkin clue?" he said under his breath, trying the handle on the next door and finding it was locked.

Crossing his fingers this was a good sign, he picked it quickly and stepped into what appeared to be a study.

He was about to open the desk drawer when he heard something. He froze, straining his ears.

Maybe it was just Sam.

Listening for a few seconds longer he heard nothing further and turned his attention back to the desk.

Upstairs Sam was just heading for the staircase when he too heard something. He stopped, pushing himself back against the wall so he was hidden in the shadows. He waited, the only sound he could hear now being the thumping of his heartbeat. He peered round the corner. Maybe it had just been Dean making a noise downstairs.

He stepped away from the wall and was about to move when he heard a soft voice behind him.

"Hello again, Sam."

He whirled round but before he could do anything the voice whispered another word in his ear and everything went black.

Dean was just about to pick up a book he'd found in the third drawer down when there was a noise out in the hall.

"Ok, I definitely did not imagine that." he said to himself, cautiously making his way around the desk and creeping towards the door.

He opened it a crack and then opened it fully when he saw Sam standing there.

"Dammit, Sam, are you trying to give me a heart attack?" he hissed.

There was no response.

He frowned, realising suddenly that Sam was standing in a weird way, his arms limp at his sides and his head hung forward so his chin was down on his chest. His hair obscured his face completely.

"Sam?" said Dean quietly, a little more cautious this time.

Something wasn't right.

"Sam's not home right now."

Dean jumped and turned round, his gun in his hand in a flash. He watched as Munro stepped out of the shadows, a humourless smile on his face.

"What have you done to my brother?" demanded Dean, keeping the gun trained on Munro as the doctor walked over to stand next to Sam.

"Let's just say we had a little condensed session in my office. Normally I would take my time of course, but that was of the essence here. It was quite simple really, especially when it came to blocking Sam's memory. That was always my favourite part. The human mind is so easy to control when you know how."

"Well you can just un-control it. Now." said Dean, aiming the gun at Munro's head.

Munro laughed, an eerie sound that had nothing to do with humour.

"Oh that is so amusing. You actually think you're in charge here. Do you take me for a fool, Dean? Do you really think I don't know what you are? I've known since the two of you arrived, conducting your little 'investigation'. I was impressed when you found my little hidden message on the tape. That was very industrious. It's always easier to work when you have a blank canvas you know, that's why I needed my patients to be unconscious while I did what was necessary."

"Victims you mean." said Dean, keeping one eye on the mad doctor and one on his brother. Sam still had yet to move.

"I wouldn't call them that. They're just a by-product really. Makes it so much easier to do my job when the police have a suspect in custody complete with damning evidence against them. Means no one looks too closely. Except you two, of course."

"So what's the deal, huh? You just do this stuff for kicks? Something to ease the boredom?"

Munro shook his head.

"Please. I'm not a murderer. No, the people who die are assisting a greater cause. You see they give me life itself. I feed off their energy, it's especially strong when someone dies a violent death you know. And with my patients unconscious when they commit the crime I can feed off of them as well. It's a perfect system."

"Right, that would be except for the poor bastard who gets their throat slit or the unlucky soul you make do the slitting in the first place." said Dean, unable to believe that after all the scenarios they'd come up with in the end it was a simple case of hypnotic suggestion and Munro feeding off the victims to stay alive.

"So righteous. So moral. Humans kill each other every day, in ways far more gruesome than the methods I employ. And really, I'm not the one holding the knife now, am I? Surely the responsibility has to lie with the person committing the crime?"

"Not when they're being controlled by you! Well you know what? It's your unlucky day because we're here to put you out of business, pal."

Munro laughed again. Dean really wished he'd stop doing that.

"Oh that is funny. Really. There is no 'we' Dean, don't you see? Sam here is under my control now and nothing you can do or say will break it. It's a shame, I had only just begun here but now I'll have to move on. So tiresome. Still, you will be a nice footnote to my little visit."

"You're not going anywhere."

"Oh I really think I am."

He leaned in towards Sam, saying something Dean couldn't make out. Sam's head snapped up and he looked at Dean, but his eyes were blank, his expression unseeing.

"Oh crap." Dean muttered, backing up a little. Sam was so gonna say 'I told you so'.

Assuming he didn't kill him first.

"Wait a second – answer me one question." said Dean, stalling for time.

Munro paused and looked towards him. Sam still hadn't moved yet.

"Very well – what is it?"

"Why eight? All these people, they have eight sessions and you always kill eight people. What's the meaning behind it."

Munro shrugged.

"Honestly? I just like the number. Has a certain, symmetry to it."

Dean blinked.

"You gotta be kidding me."

"I don't think so, do you?"

Whatever Dean had been about to say was forgotten as Sam pulled the gun out of his waistband and took the safety off. He stepped forward, jerkily, like a puppet having it's strings pulled. He aimed at Dean.

"Wait, wait, Sam – it's me. Just listen to my voice, ok? You can stop this. He has no control over you, Sam, you're better than that." said Dean, hoping he didn't sound as desperate as he felt.

Sam stepped closer still, the gun never wavering.

Dean lowered his own gun, not able to risk Sam getting in the firing line now he was effectively standing between him and Munro.

"Sam, come on, you've got to listen to me – just put the gun down, ok? We can fix this, just put it down."

Sam stopped. The gun was aimed right at Dean's head.

Dean swallowed. There was no expression in Sam's face at all, nothing in his eyes. There was no way of getting through to him.

Sam really had been right about this one.

Dean felt his stomach lurch, knowing that Munro would most likely kill Sam too once he was dead. Not that Sam would be able to live with himself anyway. He felt his eyes burn.

"Sammy, please." he pleaded, his voice barely a whisper.

Sam's finger began to tighten on the trigger.

Dean closed his eyes.