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 with no hesitation to visit someone who calls himself "The Holder of the Present." The worker will look at you vaguely; you have to ask him again. Once the worker understands your question he will lead you through a door into a hallway that looks like it's an extension of Hell itself.
In this hallway you will find nothing but darkness and the feeling of unimaginable horror. If you should hear a shriek coming from the left of you, start running towards the door you just came from or you will be devoured by demons yelling incomprehensible babble from mouths awash with vile poison.
If you should hear a shriek coming from the right of you, start running towards the door that your path leads to. Ignore the worker and keep running until you reach the door. If you should hear another shriek coming from anywhere around you, close your eyes and pray to the gods that your death will be a swift one.
Should you not hear a shriek, just follow the worker until he unlocks the door at the other end of the hallway. He will now ask you to enter, and he will leave.
In this room you will only find two things: a naked girl whose left hand is a mangled stump, seemingly torn to shreds by an otherworldly maw, and the rusted key chain she is holding. You must look at the key chain and may not avert your eyes from it. You can say nothing, except ask her this one question: "Why do they belong together?"
Now move eyesight to the face of the girl. She will look at you and tell you the most gruesome story of the present, how this present has come to be, how it is now and eventually how it will be. The girl will slowly move towards you, do not move, and stay still until she is but one footstep away from you. She will put the shredded piece of rot that was once her left hand on your shoulder. She will then whisper into your ear, "The time has come, and now you must die." Do not react to this statement. Just keep staring into her eyes and eventually you will feel something being pushed into your hand.
The key chain is Object 17 of 538. Only the keys that are meant for it can be put on it, and all other keys shall be repelled.