In any city, in any country, go to any schoolhouse you can get yourself into. Go to the principal and ask to see The Holder of Angst. If they hesitate for even a second, you're in the right place. If they refuse to acknowledge your question, ask them again. Eventually, they will grudgingly give in.
They will take you to the basement of the school. As you are descending the steps, a feeling of uncertainty will wash over you. No matter how you try, the feeling will remain in the back of your mind, growing stronger with every step. The principal will lead you to the farthest corner of the basement. The closer you get to the corner, the more light is sapped out of your surroundings. With the light goes all feeling of hope. They will frantically start brushing the cobwebs and dust off of the walls that connect at the corner. Once they complete this, both walls will have a brick with an indent just big enough to fit your hand into. The principal will leave without a word, and it will be clear to you that you are on your own from this point onward.
You will have to decide between the two walls. Be careful, though, as one contains horrors beyond the human imagination, while the other leads you forward. Either way leads to regret. If you manage to pick the door that leads onward, you will see a dark, musty corridor. It will be darker than anything you may have thought possible, but walk in as straight a line as possible. If you collide with something warm and vaguely human, stop moving. Do not move, or else you shall regret your very existence.
If you remain still, the warm-blooded mass should vanish, as if in a mist. Once this happens, speed up your pace. You will eventually think that you see light, but it is simply a trick. Do not go towards the light, for if you do, your very essence shall be in peril. At the end of this tunnel, you will feel what seems to be a door. It will be reminiscent of a medieval dungeon, with a small barred window and a wooden plank keeping the door from opening.
Once you have made it this far, there is no turning back. You cannot do anything other than unbar the door and walk inside. Once you pull the door shut behind you, there will be a deep voice in your ears, speaking a language you will not understand. It will sound as if it is everywhere and nowhere, and its incomprehensible words shall chill you to your bones. Do not move. Do not speak. Wait until the voice is done until you so much as breathe. If you do not follow these instructions, your last sound shall be tormented screaming. When the voice finishes, wait a moment. Turn slowly and face The Holder of Angst. He will be wearing torn strips of cloth, and his body will be scarred. He will look at you with eyes so full of grief and sorrow, you may almost cry yourself. Do not.
He will start speaking about his life, but his voice will be but a whisper. He will describe torments too horrific to understand, terrors that will make your ears bleed, but listen. Listen, and do not close your eyes or cover your ears, for you won’t need them if you do. During his story, he will cling to your shirt and ask you to help him escape his personal Hell. Stay silent, as this is but a ruse.
Once he is finished, he will curl into a fetal position and sob quietly. You have only a small amount of time until his crying drives you mad. Ask him, “What will happen if they are brought together?”
The Holder will be standing, even though he was just in a ball on the floor. His face will contort with an odd mix of rage and fear. He will run around, throwing unseen objects around the small, empty room. You will hear porcelain, glass, even wood break and shatter around you, even though there is nothing there. He will be ranting loudly in a language that was not meant for human ears. Again, wait. Stay still and silent until his fury is released.
The moment he is done, he will sit down. He will begin to explain the reasons why They should never have been created, the atrocities they have caused and the unimaginable power they contain. He will stop on occasion to sob or throw another imaginary-yet-real object, but he will not be done. No, his madness has been driven far too deep to be done in a matter of minutes.
He will speak for what seems like hours, and then days. Those days will turn into months, and into decades, and into millennia. You must not falter, no matter how long it seems you have been standing there. Once what seems like an eternity has passed, he will stand slowly, and walk to you. He will lightly touch the sides of your head with his palms, and knowledge will flow through your very being. The Holder will look at you with a look of blissful relief, as his madness has finally left him. The moment you blink, he will be gone.
The knowledge he has given you is Object 501 of 538, and it must never be reunited with the others, for reasons which you will now fully understand. This understanding will eventually drive you to insanity.