Lower New York
From the research files of Michel Wibert, hand-written:
Sewer
There is a bar on West 145th street, on the Hudson River Riverbank State Park. Visit the bar on the thirteenth of the month. Bring with you a bottle of spray deodorant and another of industrial chlorine compound, such as is used in swimming pools. Thirty-two ounces of the latter should suffice. Between two and two-fifteen on the morning of the fourteenth, if you have been within the bar since at least midnight, visit the bathrooms along the back hallway. There will be four of them - Men, Women, Handicapped unisex, and Other. If you are there at any other time, there will be only three doors.
Enter the door marked Other.
You will find yourself in a small alley. A small person, perhaps four feet tall, dressed in rags which cover every part of them including their face, will be waiting. Hand them the deodorant you have brought, and follow as they lead you out the alley mouth onto the deck of the park.
The Riverbank Park is built atop the North River Wastewater Treatment Plant. You will be shown to a spot in the center of one of the park's squares with a hatch in the middle. Your guide will point once at the hatch and continue on on errands of their own. Enter the hatch. Do not produce light of any kind. Follow the ladder to the bottom, closing the hatch after you, and when you reach the bottom, follow the corridor you find yourself in. After some yards of travel, you will reach a vertical hatch. Open it and enter.
You will be in a room with several control systems around the walls. The walls will be covered in a thick coating of a substance which may be blood. Do not touch it. Move to the center of the room and look down; enter the trapdoor you see there.
At the bottom, you will find yourself facing a sewage treatment vat. After some minutes, the contents of the vat will begin to heave, and then will raise themselves up above the rim in a rough mound shape. The creature will spot you, and will stop moving.
You have two choices. If you throw the open bottle of chlorine into the vat, the creature will shriek in pain as it dies, sinking slowly back into the depths. If you carefully hold out the closed bottle, indicating restraint, the creature will snatch it from you, examine it, and then lay a pseudopod against your skull before sinking back into the vat.
The only way out of the room is to wait for the creature to subside, then jump in the vat, which is a final stage of the treatment. There is a grating at surface level which can be moved aside, allowing you to exit via a sluice into the Hudson river. It will be a swim of several hundred yards to return to the shoreline and easy egress from the river.
If you chose to slay the creature, the denizens of the New York City sewer system will recognize you as their king and will assist you when they can. However, they will also seek out your aid when they need it, no matter where you are or what you are doing - and failing to assist them when they call will cause them to decide that as a king, you should remain on your throne, where you will wait for a seeker to free or kill you.
If you chose restraint, the King's touch will make you one of His guard. You will be able to tell, with the precision of a gas chromatograph, the component contents of any liquid. You will, however, be forced to swallow the liquid to determine this, and although you will never suffer from poisoning, your normal sense of taste and revulsion will remain. You will also, until the end of your days, exude a slight odor of the King's throne - the final treatment vat. No cleansing will remove it; only enormous applications of scent will cover it.
If you touch the coatings on the wall of the control room, you will reek of primary sewage for the rest of your time, and the King will not approach you.
Gas
If you explore upper Harlem, you will come to a building within some ten blocks of the Collyer Brothers original domicile. It is the decaying remains of a stately townhouse, alone on a block of which half has been turned into a half-hearted park and the rest is empty lots. Knock twice on the door on the day before a moonless night.
When the door is answered by an expressionless old black woman, tell her you are there to read the meter. She will show you slowly to the basement of the house. Do not look into any of the rooms you pass, whatever you do.
In the basement, she will point out the meters in one corner and then leave you, shuffling slowly upstairs. There are three meters there - one for water, one for gas, and one which reads simply 'thaums.' Opening the third meter and moving the indicator wheel back at least one hundred thaums will take roughly a year from your life, but will grant you the ability to sense and in some small manners control the flow of energies that surround you in New York.
If you instead leave the room with the meter unchanged and return upstairs, the woman will silently hand you several thousand dollars in old-fashioned but negotiable U.S. currency, and will not let you leave without accepting her payment of her bill. However, the money is cursed; once you accept it, you will be marked as a victim for any practitioner who also despises the utility company.
And there are more of those in New York than you might think.
Electric
Find the manhole under service by a 1950s utility van during the cold fall months, in Manhattan. The manhole will be blocked off by cones and warning tape, the van backed up to it with the doors open on a dark space crammed with tools and parts, but no technician will be in evidence. Do not remove anything from the truck except for the sole 1-inch open-head wrench. Take this with you, step over the tape and climb the ladder down into the manhole. It will be larger than you expect. Below, you will hear commotion and shouting.
When you reach the bottom, you will see lights down a utility tunnel, around several corners. Follow the light. When you reach the end of the tunnel, you will find two technicians attempting frantically to control a dead short in a power main - six hundred volts AC at 60 Hertz, some ungodly number of amperes. One will be shouting to the other for the tools he needs; the other will be reminding the first to be careful.
Eventually, the technician working on the short will need a 1-inch open-head wrench. The second technician will say that he doesn't have one. If you step forward and offer the wrench, the first technician will snatch it from you, turn back, and continue work. The short will catch him, and he will be thrown backwards, although the circuit will be safed. He will recover, thank you for the wrench, and then ask what you're doing there. Tell him that you are 'from Central.' He will nod and they will both accept this.
Once they have left to head back for the surface, retrieve the wrench. It will have been altered by the electric arc, although it will be safe to retrieve. The end will resemble nothing so much as a blob of mercury, but it will fit any fastener or lock, and will be able to open it as if it were purpose-built to do so.
You may take the wrench with you. Be warned, however, the wrench emits an unknown form of radiation; after twenty-four cumulative hours of carrying the wrench on your person, you will begin to suffer the effects of radiation sickness. Forty-eight more will be lethal. No known shielding works, but if the wrench is not being carried (for example, is being stored in a cabinet) it will not affect anyone until it is moved.
If you ignore the technician's request for the wrench and step forward, he will frantically indicate the critical 1-inch bolt. Place the wrench on the bolt and tighten it. You will suffer an enormous shock, but will wake up on the surface street, the manhole closed and the truck nowhere in sight. The hand and arm you used to wield the wrench will be toughened, almost fibrous; in fact, the surface of your arm up approximately midway up the forearm and your hand will be surfaced in what appears to be asbestos, with all the advantages and disadvantages that that entails. The asbestos will not enter your body directly, but any damage or wear on that hand will create dust, which can be breathed.
As partial compensation, you will be able to guide electricity with your changed hand and your will, to some degree which can be improved with practice. Careful, however - if you attempt to interact with too much charge, your resistance will fail. There is no way to know in advance what that level will be.
Pickman's Nodegel: The 2009 Halloween Horrorquest