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 someone who calls herself "The Holder of Nothing." Should a look of sheer, primal disgust mar the worker's expression, you will then be taken to a separate building, one that appears to be an old, wooden outhouse. Inside will be a seemingly endless corridor that far exceeds the length of that outhouse.
The corridor will be completely silent. Attempting to make any sound at the wrong time is a grievous, lamentable mistake. You will notice the lights in the corridor getting brighter and brighter as you make your way down towards the end; eventually, you will find yourself blinded by their brilliance. If, at any point the lights go out, quickly shout out, "No! Stop! What you are doing is wrong!" while backing away. If the lights do not come back on, bolt for the door you came in through. It should still be open; hopefully you aren't far enough down the hallway for it to close on you. If it does close, an eternity in Hell would be preferable to what you will suffer.
If the lights come back on, continue walking down the corridor. At the end of the hall lies a cell; the worker will open its door for you while glaring at you in disgust. Inside the cell will be a mad pastiche of colors, arranged in several harlequin-like formations. You must not be distracted by them, for at the center of the room is a naked young woman, slathered in blood and bound by strips of human sinew, and you would be better off not knowing what will happen if you take your eyes off of her face for even a moment. Focus on her, and ask: "What were they when they were one?"
She will look you in the eye and speak the answer in incredible detail. It will be unlike anything you have ever heard, leaving you on the verge of both ecstasy and agony. It is not uncommon for a Seeker to lose themselves in the euphoria. But you mustn't let your focus break, and you must take special care not to look upon her tattooed chest. Your mind will tempt you to gaze upon it, but you must resist, for if you fail, she will flay you alive and add your mutilated flesh to her bindings, and you will remain trapped with her, fully conscious, for the rest of time.
That tattoo is Object 4 of 538. They desire to be one again, but they mustn't.