Object 336
The Holder of Skin
In any city, in any country, go to any mental institution or halfway house you can get yourself to. When you reach the front desk, ask to visit the one known as "The Holder of Skin". If the clerk looks up to you, you should not have come. If the clerk does not acknowledge your presence, leave.
Outside, you will find yourself in a large canvas tent. Surrounding you on all sides will be a number of picnic tables, populated by everybody you have ever cared for; pick the one you love the most and hold them until the screaming begins. Do not choose incorrectly. Do not close your eyes. Your eyelids will be pulled from your head and you will see anyways. Do not let your loved one go. Eventually, they will begin to slide from your hands and you will fall unconscious.
When you awake, you will be lying naked in the desert, beasts tearing at your skin. Their teeth shall be made of glass, their skin of burning charcoal, their eyes of razor wire. If their chattering does not burst your heart, you are damned. Scream and they will leave you, the baking sun and your agonized nerves the only solace left. Hold your silence while they go about their word and a man will come to shoo them away. When they are gone, reach up and grab his arm, no matter what it feels like. Ask him this question before he pulls away: "Will I know?"
He will laugh at you before giving your skin back. Bite your tongue against the rending sand until he leaves, and then stand. In your hands will be a box. Turn around and put it on the clerk's desk. When she permits you to go, one of your teeth will fall out.
The tooth is Object 336 of 2538. Now you know where to bite.