A/N: I haven't written a Castle Fic in quite awhile, so of course I dive in with a 50k case-fic [for the Castle Summer Hiatus 2015 Ficathon]. Takes place late in S4, about the time of Undead Again/Always...

I will kill the first one with air...

William Peterson hates driving. It was a waste of time, he once admitted to a colleague. He had a Maybach Mercedes with a driver on call. Why should he drive himself? And yet, there he will be, walking towards the BMW 740 (his idea of a middle class car) he'd drive the 8 blocks to his Central Park apartment. Driving was bad enough, but he certainly wasn't going to take a cab or the subway.

Peterson will be driving because, recently, a small group of concerned citizens have approached him about a possible mayoral run. Bloomberg had won, after all, so there was precedent for another billionaire, and Peterson has all the right credentials, especially in comparison to Weldon. He would have to tone down a bit of his more ostentatious habits; maybe skip the helicopter trips to the Hamptons for a while? Skip the stories about skiing in GStaad?

I am perfectly fine with all of this. Gives me an easier opportunity.

Peterson leaves his car in the same spot, near the far end of his trading firm's parking garage, away from the areas that were well lit and monitored by camera. It won't be difficult to get into the garage or the car, and then to wait for Peterson in the back of the BMW, directly behind the driver's seat, crouched forward, mostly in the footwell. I'll be hidden in the shadows. There will be a small chance he'll see me when he opens the door - the interior lights will come on immediately.

But he won't. He's spent his life removing anomalies, so that he's never distracted. There will be no reason to look for me, so he won't.

He will leave the elevator at five after seven, same as always, and use the key fob to open the door from a few feet away. He'll open the door and toss his briefcase in the passenger seat with the casual disinterest of anyone embarking on an unpleasant task. As soon as he sits, I'll have my left arm up around the headrest, pinning his head back. My right arm will come around and push something sharp right into the soft flesh below his jaw.

He will yelp, startled. He's a cerebral man, not used to anything physical. I'll pull my left arm down. "I have a gun pointed at your spine through the seat. You do anything I don't like, I'll make sure you never walk again," I'll tell him in a harsh whisper, not that he'd be likely to recognize my voice anyway. "You do anything I don't like, and you're dead."

"You aren't going to get..."

I could recite what he'll say verbatim, but what's the point? You know this part. You've seen a TV show. Most of our life is a cultural script we picked up from some screen. He'll beg, bribe, and threaten. Finally, he'll shut up.

Once the whining is done, I'l have him drive to a warehouse by the East River. The drive doesn't take long, though the wait will hurt, as this will be my most vulnerable time. It will take some unpleasant balancing to keep the syringe pinned to his neck with my body ducked low enough as not to be seen through the back windows. My quads will burn, but I'll handle it. He won't recognize the warehouse, even though he, or rather one of his holding companies, owns it. For him it's just an asset on paper, tied to something physical out the world he need not concern himself with. He won't be a hero. He'll drive out of the lot and across town without incident.

We will be at the warehouse thirty minutes later.

He'll pull through the loading door, and park. I'll have him grab his phone from the passenger seat, tell him what I want. He will transfer the funds for me.

"This won't work," he'll say, or something like it. "You'll need more than my authorization. You'll need..."

William Peterson is a lot things, but stupid isn't one of them. It will be around then that he'll realize who I am, or at least one of the few people I could possibly be. But it won't matter. He'll have sent the authorization, or I'll push until he does.

That's when I will jam the syringe into his carotid artery and push the plunger.

The syringe will be empty. Or rather, it will be filled with air. You know how nurses tap on the needle before an injection? They are removing the air. An air bubble in your bloodstream is like a little traveling bomb. I'll shove a massive one into his, and a few seconds later, it will hit his brain, causing a massive stroke.

A stroke is a risky way to kill someone. People survive them too often. But they are a great way, when they are as large as the one I will induce, to incapacitate someone. Once he is out, I will be able to leave my message with him, and then if I have to finish the job, I can do so simply by gently pinching his nose and holding his mouth shut. The rest will just be stage setting.

So why am I writing all of this down?

There is no sin greater than pride. Many a mission has been destroyed because someone felt a need to brag, even if just to a bartender over a whiskey. I am no different. I know my own sins. My mission is vital, and I feel a certain need to tell everyone about it, although those that fail to see what I am trying to accomplish may try to stop me. Will try to stop me. So I write here, where there is no connection to me, where it is too late to stop me, where it is too late to find me. I write here to burn off the urge to talk elsewhere.

And if nothing else, it helps me clear my head before I move on to the next one...